US20030236489A1 - Method and apparatus for closed-loop flow control system - Google Patents

Method and apparatus for closed-loop flow control system Download PDF

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Publication number
US20030236489A1
US20030236489A1 US10/177,544 US17754402A US2003236489A1 US 20030236489 A1 US20030236489 A1 US 20030236489A1 US 17754402 A US17754402 A US 17754402A US 2003236489 A1 US2003236489 A1 US 2003236489A1
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United States
Prior art keywords
flow rate
fluid
delivery
set forth
flow
Prior art date
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Abandoned
Application number
US10/177,544
Inventor
James Jacobson
Tuan Bui
Stephen Garchow
Atif Yardimci
James Slepicka
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Baxter International Inc
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Baxter International Inc
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=29734427&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US20030236489(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Baxter International Inc filed Critical Baxter International Inc
Priority to US10/177,544 priority Critical patent/US20030236489A1/en
Assigned to BAXTER INTERNATIONAL, INC. reassignment BAXTER INTERNATIONAL, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SLEPICKA, JAMES S., YARDIMCI, ATIF, GARCHOW, STEPHEN R., BUI, TUAN, JACOBSON, JAMES D.
Priority to TW092115004A priority patent/TWI238069B/en
Priority to CNB038141477A priority patent/CN100548399C/en
Priority to EP03736858A priority patent/EP1515762A1/en
Priority to AU2003237402A priority patent/AU2003237402A1/en
Priority to KR10-2004-7020727A priority patent/KR20050014869A/en
Priority to PCT/US2003/017740 priority patent/WO2004000394A1/en
Priority to MXPA04012657A priority patent/MXPA04012657A/en
Priority to AR20030102217A priority patent/AR040448A1/en
Publication of US20030236489A1 publication Critical patent/US20030236489A1/en
Priority to US11/333,594 priority patent/US7879025B2/en
Priority to US12/053,134 priority patent/US8231566B2/en
Priority to US12/053,120 priority patent/US8672876B2/en
Priority to US12/053,156 priority patent/US8226597B2/en
Abandoned legal-status Critical Current

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/14Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
    • A61M5/168Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body
    • A61M5/16886Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body for measuring fluid flow rate, i.e. flowmeters
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/14Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
    • A61M5/168Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body
    • A61M5/172Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body electrical or electronic
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/14Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
    • A61M5/168Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05DSYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00Control of flow
    • G05D7/06Control of flow characterised by the use of electric means
    • G05D7/0617Control of flow characterised by the use of electric means specially adapted for fluid materials
    • G05D7/0629Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
    • G05D7/0676Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on flow sources
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2205/00General characteristics of the apparatus
    • A61M2205/02General characteristics of the apparatus characterised by a particular materials
    • A61M2205/0244Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2205/00General characteristics of the apparatus
    • A61M2205/02General characteristics of the apparatus characterised by a particular materials
    • A61M2205/0272Electro-active or magneto-active materials
    • A61M2205/0294Piezoelectric materials
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/14Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
    • A61M5/142Pressure infusion, e.g. using pumps
    • A61M5/14212Pumping with an aspiration and an expulsion action
    • A61M5/14236Screw, impeller or centrifugal type pumps

Definitions

  • the invention relates generally to delivering fluids to a patient and, particularly, to closed-loop flow control systems and methods for delivering medical fluids to a patient at a controlled delivery rate.
  • a variety of fluid delivery systems are currently being used in the medical field for delivering medical fluids (containing medication, nutrition, saline, and so on) to human and veterinary patients. It is often desirable to administer such medical fluids at relatively precise delivery rates. In some cases, the rate of delivery may be exceptionally important. In recent years, it has also been found to be advantageous to use various types of infusion pumps to administer medical fluids automatically, over extended periods of time.
  • a typical infusion pump delivers the medical fluid into the patient's venous system using a delivery channel which usually comprises an administration tube (e.g., a polyvinyl chloride tube) connected to the patient using some form of catheter, needle, or the like.
  • an administration tube e.g., a polyvinyl chloride tube
  • infusion pumps and similar devices known in the art have typically not provided closed-loop flow control to achieve precise delivery rates. Rather, flow control has been open loop because actual flow rate information has not been used in controlling the infusion pump.
  • a typical accuracy of such systems, in terms of flow rate is normally no better than about +/ ⁇ 5%, and requires relatively sophisticated (and costly) mechanical components and tight material/geometry controls (e.g., of the tubing) to achieve that rate.
  • ambulatory pumps typically achieve accuracies of +/ ⁇ 6-8%.
  • non-ambulatory pumps often do not achieve a five percent accuracy range at low flow rates or over longer time periods due to modification of the tubing material over time.
  • a typical peristaltic type pump requires repeated deformation of the administration tube. This deformation process changes the elastic recovery properties of the tube, resulting in changes in the volumetric output of the pump over time.
  • One volumetric pump available from the assignee of the present application has a specified rating of +/ ⁇ 5% at 1-1200 ml/hr and +/ ⁇ 10% at 0.1-1 ml/hr.
  • Another pump available from the assignee of the present application has a rated accuracy of +/ ⁇ 5% for the first 24 hours of use and +/ ⁇ 10% thereafter.
  • Pat. No. 5,482,841 discloses a volumetric-type infusion pump.
  • An example of an ambulatory infusion pump is a pump sold under the mark IPUMP by the assignee of the present application.
  • An example of an ambulatory pump may also be found in U.S. Pat. No. 5,993,420.
  • a typical PD sensor includes two complementary rotating elements that, when exposed to a fluid flow, allow a relatively well-defined volume of the fluid to transfer from one side of the sensor to another side of the sensor with each rotation (or partial rotation) of the rotating elements.
  • One advantage of PD sensors is that they support a variety of fluids with substantially equal levels of accuracy. In the prior art, such devices typically measure large fluid flow rates and the requisite level of precision is achieved by conventional precision machining and polishing techniques. In fact, components must sometimes be matched to ensure minimal clearances of the rotating elements and inner housing geometry. Such conventional PD sensors, however, are not well-suited for use in high-precision medical fluid delivery systems.
  • a commercial infusion pump may require the ability to deliver fluids over a wide range of delivery rates (e.g., 4 logs), including very low flow rates.
  • delivery rates e.g. 4 logs
  • conventional manufacturing techniques tend to be expensive and, therefore, are not well-suited for use in manufacturing disposable items.
  • micro electromechanical system MEMS
  • micro molded devices MEMS devices
  • LIGA processing Lithographie Galvanoformung Abormung was developed in Germany in the late 1980s and translates roughly to the steps of lithography, electroplating, and replication. LIGA allows for the formation of relatively small, high aspect ratio components.
  • a photoresist layer e.g., an acrylic polymer such as polymethyl methacrylate (PMMA) is applied to a metallized substrate material.
  • PMMA polymethyl methacrylate
  • the photoresist layer is selectively exposed to synchrotron radiation (high-energy X-ray radiation) via a mask pattern to form the desired high aspect ratio walls.
  • synchrotron radiation high-energy X-ray radiation
  • the exposed sample is thereafter placed in a developing solution that selectively removes the exposed areas of PMMA.
  • One development solution is 20% by volume of tetrahydro 1,4-oxazine, 5% by volume 2-aminoethanol-1, 60% by volume 2-(2-butoxyethoxy)ethanol, and 15% by volume water.
  • the sample is thereafter electroplated; metal fills the gaps within the PMMA to form a negative image.
  • the PMMA is then removed using a solvent, leaving a metal form for either immediate use or for use as a replication master.
  • the entire LIGA process is described in greater detail in chapter 6, page 341 of Marc Madou, “The Fundamentals of Microfabrication, the Science of Miniaturization,” Second Edition (CRC Press 2001).
  • LIGA has been identified for use in manufacturing micro-fabricated fluid pumps. It is believed, however, that LIGA-based micropumps have never been made available commercially. Cost is one substantial drawback of LIGA; it is believed that there are relatively few synchrotron devices (e.g., 10-15 devices) in the world. Accordingly, LIGA is fairly limited in its applicability for directly manufacturing low cost devices.
  • an improved fluid delivery system benefits from a closed-loop control process that uses flow rate information to ensure that the desired flow rate is substantially achieved. Further, in one form, such a system is constructed using one or more micro-fabrication and/or molding techniques allowing for a cost-effective, disposable administration set.
  • a system for delivering fluid at a desired flow rate from a reservoir to a delivery point associated with a patient includes a delivery channel between the reservoir and the delivery point through which the fluid is delivered to the patient.
  • a pump is associated with the delivery channel for operatively delivering the fluid to the delivery point at an adjustable output rate.
  • a flow sensor is located along the delivery channel for sensing a flow of the fluid in the delivery channel and for generating a flow rate signal indicative of a rate of flow of the fluid in the delivery channel.
  • the flow sensor comprises a positive displacement flow sensor.
  • a controller controls the pump. The controller causes adjustments to the output rate of the pump as a function of the flow rate signal whereby the desired flow rate is substantially achieved.
  • the invention in another aspect, relates to a closed-loop fluid delivery system for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube.
  • the closed-loop fluid delivery system includes fluid delivery means located along the administration tube for operatively supplying the fluid to the delivery point at a controllable output rate.
  • a positive displacement flow sensing means is located between the fluid delivery means and the delivery point for sensing an actual flow rate of the fluid in the delivery channel and for generating a flow rate signal indicative of the actual flow rate of the fluid in the delivery channel.
  • a control means associated with the fluid delivery means receives and is responsive to the flow rate signal for adjusting the output rate of the fluid delivery means such that the desired delivery rate at which the fluid is supplied to the delivery point associated with the patient is substantially achieved.
  • the invention in still another aspect, relates to a system for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube.
  • the system includes a delivery mechanism operatively connected between the reservoir and the delivery point.
  • the delivery mechanism is constructed and arranged for selectively delivering the fluid to the delivery point via the administration tube at a controllable output flow rate.
  • a closed-loop control system controls the output flow rate of the delivery mechanism.
  • the closed-loop control system includes a positive displacement flow sensor connected in-line with the administration tube for determining an actual flow rate of the fluid in the administration tube and for providing an flow rate indication reflecting the actual flow rate.
  • a reader associated with the positive displacement flow sensor receives the flow rate indication and provides a flow control signal reflecting the flow rate indication.
  • a controller associated with the delivery mechanism receives and is responsive to the flow control signal for controlling the output flow rate of the delivery mechanism as a function of the flow control signal such that the output flow rate is substantially equal to the desired delivery rate.
  • the invention in yet another aspect, relates to a method of delivering a medical fluid to a delivery point associated with a patient at a desired delivery flow rate.
  • the method includes operatively connecting a reservoir to a delivery mechanism.
  • the reservoir contains the medical fluid to be delivered to the delivery point.
  • the delivery mechanism is operatively connected to an administration tube.
  • the administration tube is in fluid communication with the delivery point.
  • the delivery mechanism receives the medical fluid from the reservoir and supplies the medical fluid to the delivery point via the administration tube at an output flow rate.
  • the output flow rate of the medical fluid in the administration tube is sensed using a positive displacement flow sensor.
  • the sensed output flow rate of the medical fluid is compared with the desired delivery flow rate.
  • the delivery mechanism is controlled such that the output flow rate substantially corresponds to the desired delivery flow rate.
  • the invention in another aspect, relates to a closed-loop flow control system for controlling a medical fluid delivery system.
  • the medical fluid delivery system delivers a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube.
  • the medical fluid delivery system includes a delivery mechanism operatively connected between the reservoir and the delivery point.
  • the delivery mechanism is constructed and arranged for delivering the fluid to the delivery point via the administration tube at a controllable output flow rate.
  • the closed-loop flow control system includes a positive displacement flow sensor connected in-line with the administration tube for determining an actual flow rate of the fluid in the administration tube and for providing an flow rate indication reflecting the actual flow rate.
  • a reader associated with the positive displacement flow sensor receives the flow rate indication and provides a flow control signal reflecting the flow rate indication.
  • a controller associated with the delivery mechanism receives and is responsive to the flow control signal for controlling the output flow rate of the delivery mechanism as a function of the flow control signal such that the output flow rate is substantially equal to the desired delivery rate.
  • the invention in still another aspect, relates to a method of detecting a blockage in a medical fluid delivery system arranged for delivering a medical fluid to a delivery point associated with a patient at a desired flow rate.
  • the method includes operatively connecting a reservoir to a delivery mechanism.
  • the reservoir contains the medical fluid to be delivered to the delivery point.
  • the delivery mechanism is operatively connected to an administration tube that is in fluid communication with the delivery point.
  • the delivery mechanism receives the medical fluid from the reservoir and supplies the medical fluid to the delivery point via the administration tube at an output flow rate.
  • the output flow rate of the medical fluid in the administration tube is sensed.
  • a determination is made whether the sensed output flow rate is indicative of a blockage in the administration tube.
  • An alarm signal is provided if it is determined that the sensed output flow rate indicates that the administration tube is blocked.
  • the invention relates to an administration set for use in connection with a fluid delivery system that is arranged for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate.
  • the fluid delivery system includes a pump having an output rate for delivering fluid from the reservoir to the delivery point and a controller for adjusting the output rate of the pump such that the desired delivery rate is substantially achieved.
  • the administration set includes an administration tube for providing fluid communication between the reservoir and the delivery point.
  • a positive displacement flow sensor is located along the administration tube and is sized and shaped for being positioned in fluid communication with the fluid within the administration tube.
  • the positive displacement flow sensor senses a rate of flow of the fluid in the administration tube and generates a flow rate signal that is indicative of the sensed rate of flow of the fluid in the administration tube such that the controller adjusts the output rate of the pump as a function of the flow rate signal.
  • the invention in another form, relates to a positive displacement flow sensor for use in connection with a medical fluid infusion system that includes an administration set having an administration tube.
  • the positive displacement flow sensor comprises a housing having an inlet port and an outlet port. The inlet and outlet ports are operatively connected to the administration tube.
  • a first rotor is positioned within the housing between the inlet port and the outlet port.
  • a second rotor is positioned within the housing between the inlet port and the outlet port. The second rotor is positioned adjacent to the first rotor, and the first and second rotors are constructed and arranged to rotate in response to a flow of medical fluid in the administration tube for detecting flow of the medical fluid in the administration tube.
  • a cover encloses the housing such that when the medical fluid flows into the inlet port it causes the first rotor to rotate and thereafter the medical fluid exits through the outlet port.
  • the invention may comprise various other devices, methods, and systems.
  • FIG. 1 illustrates one embodiment of an infusion pump suitable for use in connection with aspects of the invention.
  • FIG. 2 is a block diagram of one embodiment of a closed-loop flow control system suitable for use in connection with an medical fluid infusion pump, such as the infusion pump of FIG. 1, according to aspects of the invention.
  • FIG. 3A is a flow chart that illustrates an exemplary method of delivering a fluid to a patient in accordance with a closed-loop flow control process, suitable for use in connection with aspects of the invention.
  • FIG. 3B is a flow chart that illustrates an exemplary method of detecting and reporting a blockage/occlusion in an infusion system, in accordance with aspects of the invention.
  • FIG. 4A is a schematic representation of a top view of one embodiment of a flow sensor suitable for use in connection with a closed-loop flow control system, such as the system of FIG. 2.
  • FIG. 4B is a schematic representation of a side view of one embodiment of a flow sensor suitable for use in connection with a closed-loop flow control system, such as the system of in FIG. 2.
  • FIG. 5 illustrates an exemplary process of manufacturing a positive displacement flow sensor using a high aspect ratio lithographic process.
  • FIG. 6 illustrates an exemplary process of manufacturing a positive displacement flow sensor using a deep reactive ion etching sequence.
  • FIG. 7 is a top view of a cap piece, suitable for use in connection with a positive displacement flow rate sensor, in accordance with aspects of the present invention.
  • FIG. 1 illustrates one embodiment of an infusion pump 100 suitable for use in connection with aspects of the present invention.
  • the infusion pump 100 comprises a syringe-type infusion pump.
  • Infusion pump 100 includes a housing 102 , a display screen 104 , and a control panel 106 .
  • the control panel 106 and the display screen are used to enter set-point data for operating infusion pump 100 and for monitoring the operation of pump 100 .
  • the infusion pump 100 also includes a syringe barrel 108 for holding a medical fluid to be administered.
  • a barrel bracket 110 attaches the syringe barrel 108 is attached to the housing 102 .
  • a movable syringe driver 112 is also attached to housing 102 and is positioned in engagement with a syringe plunger 114 .
  • a driving mechanism within housing 102 is constructed and arranged so that the movable syringe driver 112 can drive syringe plunger 114 into (or out of) syringe barrel 108 in a controlled direction along barrel 108 .
  • a user loads a desired amount of the fluid to be administered into syringe barrel 108 .
  • Syringe barrel 108 is mounted to housing 102 via bracket 110 and plunger 114 is moved into position within barrel 108 .
  • Infusion pump 100 is attached to a patient 120 (e.g., a human patient or a veterinary patient) via a channel such as an intravenous PVC administration tube 122 .
  • the user enters the desired administration program on control panel 106 and infusion pump 100 controls a movement of plunger 114 via driver 112 to deliver the fluid to the patient at a programmed delivery rate corresponding to the administration program.
  • infusion pump 100 and its operation in connection with patient 120 has been generally in accordance with known infusion systems.
  • fluid delivery is controlled in an open-loop fashion-based on a desired set point without regard to actual flow rates.
  • Line 124 diagramatically illustrates a closed-loop information feedback path from a flow rate sensor 126 that is positioned for detecting a flow rate in tube 122 at a point between infusion pump 100 and patient 120 . Closed loop control using such flow information in a feedback path is discussed in greater detail in connection with FIG. 2. Also, and as also discussed in greater detail below, aspects of a sensed flow information feedback system can be used for occlusion detection instead of or in addition to flow rate control.
  • FIG. 2 is a block diagram that schematically illustrates one embodiment of a closed-loop flow control system suitable for use in connection with an medical fluid infusion pump, such as a volumetric or ambulatory type pump.
  • an medical fluid infusion pump such as a volumetric or ambulatory type pump.
  • a syringe pump does not “draw” from a reservoir. Rather, as shown in FIG. 1, the plunger of a syringe pump acts upon the reservoir to output fluid to the patient.
  • a syringe type pumps and volumetric and ambulatory type pumps are not substantial, and aspects of the invention may be employed with each of these types of infusion pumps.
  • FIG. 2 illustrates a fluid reservoir 202 connected to an administration tube 204 .
  • Arrows 206 indicate that a fluid flows in the administration tube 204 into the patient.
  • Administration tube 204 is operatively connected to an infusion pump system 208 that is positioned along the administration tube 204 .
  • infusion pump 208 includes a pumping delivery mechanism 210 . As will be explained in more detail below, there are a variety of pumping mechanisms that may be employed.
  • the pumping mechanism 210 may comprise a syringe driver driving a syringe plunger in a syringe-type infusion pump.
  • the pumping mechanism 210 is controllable/adjustable for controlling/adjusting a flow rate of the fluid within administration tube 204 to conform with a desired flow rate.
  • a flow rate sensor 212 is located in-line with administration tube 204 and receives the fluid through pumping mechanism 210 .
  • the flow rate sensor 212 preferably includes an inlet port 214 and an outlet port 216 .
  • the inlet port 214 receives flowing fluid at the flow rate provided by pumping mechanism 210 and provides flowing fluid at its output port 216 .
  • administration tube 204 comprises a plurality of IV tube pieces. A first piece of IV tube connects pumping mechanism 210 to input port 214 and a second piece of IV tube connects output port 216 to a delivery point associated with a patient 220 .
  • Other flow sensing arrangements are possible.
  • flow rate sensor 212 could be located entirely within the IV tube.
  • flow rate may be measured at any convenient point along the path because the flow rate is the same—upstream or downstream of the pump.
  • the flow rate in administration tube 204 of FIG. 2 just below fluid reservoir 202 is equal to the flow rate at input port 214 , as well as at output port 216 .
  • Some infusion pumps e.g., metering and discontinuous systems
  • an amount of compliance may exist within a disposable administration set. Therefore, in many applications there will be value in locating the flow rate sensor downstream of the pump, and closer to the patient.
  • fluid reservoir 202 , tube 204 and flow rate sensor 212 comprise part of a disposable administration set that is mounted in infusion pump system 208 .
  • a disposable set could include a variety of components including, for example, valves (e.g., normally closed valves), specialized pumping complements, and the like.
  • the set can include a reservoir; or the reservoir can be separate and integrated with the set through a spike or other connection.
  • the flow rate sensor 212 provides an indication of an actual rate of flow within administration tube 204 .
  • flow rate sensor 212 is a positive displacement flow sensor for providing a flow rate signal 224 representing the actual flow rate of fluid flowing in administration tube 204 .
  • flow rate sensor 212 can be constructed such that a varying optical contrast or electrical signal is generated by the flow of fluid. Exemplary structures and methods for providing such a flow rate signal are discussed in greater detail below.
  • flow rate sensor 212 comprises a passive device, having no electrical connections thereto.
  • a reader 230 such as an optical or electrical signal detector, is preferably positioned adjacent flow rate sensor 212 such that it can receive/detect flow rate signal 224 .
  • the reader 230 communicates the detected flow rate signal 224 to a controller 232 via a communication path.
  • reader 230 receives flow rate signal 224 from flow rate sensor 212 and supplies a flow control signal 234 to the controller 232 .
  • the flow control signal 234 preferably provides substantially the same information as the flow rate signal 224 —an indication of the actual flow rate of fluid in tube 204 .
  • the flow control signal 234 comprises one or more pulses.
  • controller 232 is programmed to interpret each pulse as corresponding to a fixed volume of fluid flowing through sensor 216 . Accordingly, controller 232 can determine the actual flow rate sensed in the administration tube as a function of the number of pulses received from reader 230 . In such an embodiment, an indication of the cumulative flow volume delivered is provided by the number of pulses, and an indication of the instantaneous flow rate is determined by the time period of the pulses.
  • the communication path between reader 230 and controller 232 comprises a wired communication channel 236 .
  • the communication path comprises a wireless (e.g., IR, RF, and/or the like) communication channel 238 .
  • the wireless channel 238 may be advantageous, for instance, in systems in which flow rate sensor 212 and/or reader 230 are located at a distance from controller 232 and/or when physical connectivity is undesirable.
  • One exemplary wireless communication channel uses BluetoothTM wireless technology.
  • BluetoothTM is a wireless specification from a trade association, Bluetooth SIG, Inc. In general, it is a low cost and low power specification, operating in the unlicensed 2.4 GHz spectrum, and using spread spectrum frequency hopping techniques.
  • the controller 232 is operatively connected for automatically controlling pumping mechanism 210 . This is illustrated schematically as a pump control signal 240 on line 242 between controller 232 and pump 210 . It should be understood that a wide variety of devices may serve as controller 232 .
  • controller 232 may be embodied by a processor (e.g., a microprocessor or microcontroller), discrete logic components, application specific circuitry, programmable logic devices, analog circuitry, or combinations thereof.
  • a motor-based pump could be controlled by adjusting the motor rotation rate or a cycle time associated with the motor. If a certain type of MEMS-based pump is employed, for example, control may be achieved by adjusting the frequency of a piezo oscillation.
  • the system can also be configured to provide a status signal.
  • controller 232 provides a status signal, such as an alarm signal 250 , on a line 252 (and/or a wireless channel 256 ) to a status monitoring device 254 .
  • the status monitoring device 254 comprises an audible alarm system for providing an audible alarm in the event of a malfunction.
  • Status monitoring device 254 may also comprise other audio, visual, audio-visual, and vibrating devices such as, for example, CRT monitors, pagers, horns, buzzers, speakers, computers, portable telephones (e.g, cellular telephones), personal digital assistants (PDAs), and the like.
  • controller 232 provides an alarm signal to cause an audible and/or visual alarm to be activated if controller 232 is unable to control pump 210 to achieve a desired flow rate.
  • a condition can occur if an occlusion or blockage in administration tube 204 prevents an adequate flow of fluid to patient 220 .
  • Such a blockage may include complete blockages, as well as partial blockages affecting flow rate.
  • Alarm conditions can be programmed to occur for a variety of other reasons, such as when the fluid supply in reservoir 202 becomes depleted to a level at which pump 210 can no longer deliver the fluid at the desired delivery rate. It should be appreciated, however, that status indications other than failures or improper operational conditions may also be provided.
  • a status signal could be used to provide an indication at a remote monitoring station of the current sensed flow rate or another indication regarding the operation of the system.
  • sensed flow rate information can be used to anticipate when the fluid supply will be depleted, such that a suitable indication is provided in advance of such event.
  • a patient is operatively connected to administration tube 204 (e.g., via a catheter inserted at a desired delivery point associated with the patient).
  • Reservoir 202 contains a fluid to be administered to the patient and is operatively connected to administration tube 204 and pumping mechanism 210 .
  • a desired delivery rate is entered on a control panel associated with the pump (see, e.g., FIG. 1).
  • control panel 106 and display 104 cooperate to provide a user interface to facilitate entering set-point data for use by pump 100 .
  • controller 232 uses set-point data representative of the desired delivery rate in combination with the flow control signal 234 for controlling the system.
  • flow rate sensor 212 senses the flow rate of the fluid in tube 204 and periodically (or continuously) outputs flow rate signal 224 which is received/detected by reader 230 .
  • reader 230 comprises an optical reader for detecting the optical signal indication generated by flow rate sensor 212 .
  • reader 230 illuminates flow rate sensor 212 with a light and examines the light reflected by the flow rate sensor to determine the flow rate signal 224 .
  • Reader 230 thereafter provides flow control signal 234 to controller 232 .
  • This flow control signal 234 is functionally related to the flow rate signal 224 and, therefore, provides an indication of the actual flow rate of fluid into patient 220 .
  • controller 232 is able to monitor the actual flow rate of fluid in tube 204 . With this information, controller 232 is able complete a closed-loop control path with pump 210 .
  • controller 232 executes a control scheme for generating the pump control signal 240 to adjust the pumping action of pump 210 so that the actual flow rate, as measured by flow rate sensor 212 , more closely matches the desired flow rate. It should be understood that a variety of control schemes may be employed, depending upon goals.
  • the degree of accuracy with respect to controlling flow rate can be varied, depending upon usage. For example, if gross accuracy (e.g., +/ ⁇ 15%) is acceptable, the closed-loop feedback control could be disabled in software (e.g., via a control panel input) or by eliminating flow rate sensor 212 from the administration set. Gross accuracy can also be achieved by adjusting control parameters, such as sample rates and so on. On the other hand, if a relatively high degree of accuracy is desired (e.g., +/ ⁇ 2%), the controller is preferably programmed/configured to tightly control the pumping action of pump 210 . It should be appreciated, therefore, that an infusion pump system, embodying aspects of the invention can be reconfigured to accommodate a wide variety of needs, thereby improving the usefulness of such a system.
  • gross accuracy e.g., +/ ⁇ 15%
  • the closed-loop feedback control could be disabled in software (e.g., via a control panel input) or by eliminating flow rate sensor 212 from the administration set. Gross accuracy can also be achieved by
  • flow rate sensor 212 is compatible with a wide variety of fluid delivery profiles, including constant profiles, pulsatile profiles, and other time-varying and non-uniform delivery profiles. With such profiles, including pulsatile flow profiles, the pump may need to ramp up and/or down from its running rate faster than with other delivery profiles. Thus, knowledge of actual flow rate helps to ensure tighter control of the profile.
  • controller 232 can monitor the actual flow rate in tube 204 (as detected by flow rate sensor 212 ) over time and control the pumping action of pump 210 to ensure that the actual flow rate conforms to the desired delivery profile.
  • closed-loop control allows infusion pumps to be manufactured with a greater degree of flexibility in terms of manufacturing tolerances and the like. In some prior art systems, delivery accuracy is attempted by tightly controlling the tolerances of the mechanical pumping components and mechanisms, which can be expensive. With flow rate feedback control according to aspects of the invention, on the other hand, infusion pumps can be made with less precise (and therefore less expensive) components and mechanisms, yet still achieve a high degree of accuracy in terms of fluid delivery rate control.
  • tubing would not need to be as precise and the integration of the pump and disposable components would be less dependent upon the materials used in the disposable components.
  • PVC tubing provides certain advantages in prior art systems, so the design of the infusion pump may need to be tailored to be compatible with such tubing. This type of engineering expense may be eliminated if PVC tubing is no longer necessary.
  • a blockage a complete blockage and/or a partial blockage—between the fluid reservoir and the delivery point can result in an unacceptably low rate of flow.
  • Such blockages are sometimes referred to herein as occlusions but may be caused by a variety of conditions, including a kink in tube 204 .
  • Prior art attempts to detect occlusions rely on pressure sensing, which requires a relatively large change in the pressure in the tube to be detected.
  • a disadvantage of pressure sensing is that it may take a long time for the pressure in the tubing to increase to a detectable level.
  • a blockage e.g., a complete and/or partial blockage
  • a blockage associated with a 0.1 ml/hour delivery rate could take two hours or more to be detected with a typical prior art pump.
  • the sensitivity of a pressure sensing system is increased to reduce response times, more false alarms are likely to be experienced.
  • a closed-loop flow controller is able to rapidly detect blockages (complete and/or non-complete blockages, even at very low delivery rates) because flow rate sensor 212 detects an actual flow rate and does not require a pressure build up.
  • One embodiment of flow rate sensor 212 is capable of providing accurate measurements (e.g., better than +/ ⁇ 5%) over four logs of range. For example, a pump using such a flow sensor supplies fluid from about 0.1 ml/hr up to about 2000 ml/hr. Thus, flow rate sensing and occlusion detection is possible at low flow rates, as well as at higher flow rates.
  • FIGS. 1 and 2 For convenience, the foregoing descriptions of FIGS. 1 and 2 have been generally provided in terms of embodiments comprising syringe-type infusion pumps and ambulatory and volumetric pumps.
  • One type of prior art syringe pump is more fully described in commonly assigned U.S. Pat. No. 5,533,981.
  • closed-loop control systems and methods may be adapted for use with other types of medical fluid delivery systems.
  • Such systems include, for example, rotary and linear peristaltic-type pump systems, valve-type pump systems, piezoelectric pump systems, pressure-based pump systems, and various motor and/or valve driven systems.
  • a peristaltic-type pump manipulates the IV administration tube to achieve a desired flow rate.
  • a peristaltic-type pump employs an array of cams or similar devices that are angularly spaced from each other.
  • the cams drive cam followers that are connected to pressure fingers. These elements cooperate to impart a linear wave motion on the pressure fingers to apply force to the IV tube. This force imparts motion to the fluid in the IV tube, thereby propelling the fluid.
  • Other forms of peristaltic-type pumps use different pressure means such as, for example, rollers.
  • valve-type pumps employ pumping chambers and upstream and downstream valving (e.g., electronically controlled valves) to sequentially impart a propulsion force to the fluid to be delivered to the patient. It is also possible to use a valve in connection with a gravity-fed delivery system in which gravity provides the motivating force and one or more valves are used to control the flow rate. Piezoelectric pumps control pumping by varying the magnitude of an applied voltage step. Pressure-based pumps adjust flow rate by controlling the pressure applied to a fluid reservoir (sometimes called “bag squeezer” systems).
  • the closed-loop control systems and methods described herein may be used in ambulatory infusion pump systems and volumetric infusion pump systems.
  • the components illustrated in FIG. 2 are grouped for convenience.
  • the status monitor device 254 could be made integral with the rest of the infusion pump system 208 .
  • reservoir 202 could be integral with the pump unit or separate.
  • the barrel of the syringe acts as a reservoir, but is physically mounted to the infusion pump housing.
  • the reservoir is typically contained within the pump boundaries.
  • the reservoir is generally more external to the pump boundaries.
  • FIG. 3A is a flow chart that illustrates an exemplary method of delivering a fluid to a patient in accordance with a closed-loop flow control process.
  • a fluid reservoir e.g., a fluid bag
  • an infusion pump which, in turn, is connected to the patient (blocks 302 , 304 ).
  • fluid delivery begins (block 308 ).
  • the actual flow rate of fluid to a delivery point associated with the patient is sensed (block 310 ).
  • a positive displacement flow rate sensor located in-line between the patient and the pump can be used to sense actual fluid flow and provide a flow rate indication to a control device.
  • the actual flow rate is compared to the desired delivery rate at block 312 . If the actual flow rate is appreciably greater than desired (block 314 ), the infusion pump is adjusted such that its output rate is reduced (block 316 ), thereby reducing the actual delivery rate to more closely match the desired flow rate. If, however, the actual flow rate is appreciably less than the desired rate (block 318 ), the infusion pump is adjusted such that its output rate is increased (block 320 ), thereby increasing the actual delivery rate.
  • the method also includes using a disposable administration set that includes, for example, an administration tube and an in-line flow rate sensor (e.g., tube 204 and flow rate sensor 212 of FIG. 2) such that, upon completing the fluid delivery process, the administration set is discarded.
  • a disposable administration set that includes, for example, an administration tube and an in-line flow rate sensor (e.g., tube 204 and flow rate sensor 212 of FIG. 2) such that, upon completing the fluid delivery process, the administration set is discarded.
  • FIG. 3B is a flow chart that illustrates an exemplary method of detecting and reporting a blockage/occlusion in an infusion system, in accordance with aspects of the invention.
  • the process is similar in several aspects to the method illustrated in FIG. 3A.
  • the sensed actual flow rate is compared to an occlusion/blockage threshold reference.
  • This threshold can be a predetermined value (e.g., a fixed number or a fixed percentage of the desired delivery rate), or a dynamically determined value (e.g., a time varying threshold).
  • a blockage is declared and an alarm condition is triggered (blocks 332 , 334 ).
  • a change in the sensed flow rate e.g., a slope
  • the controller preferably accounts for this fact.
  • flow rate comparisons (e.g., block 314 or block 330 ) need not be referenced to a fixed value. Rather, other flow rate comparisons are possible. Such comparisons include comparing the flow rate to an acceptability range and/or a time varying reference. Further the reference to which the actual flow rate is compared may be programmed by the user or pre-existing and used in connection with an algorithm or treatment protocol.
  • FIGS. 4A and 4B are schematic representations of one embodiment of a flow rate sensor 402 suitable for use in connection with a closed-loop flow control system, such as the pump system 208 illustrated in FIG. 2.
  • Flow rate sensor 402 preferably comprises a micro-fabricated MEMS device or a similar micro-molded device (e.g., an assembly of micro-molded components). Exemplary fabrication techniques for manufacturing such a flow sensor are discussed below.
  • Flow rate sensor 402 has an inlet port 404 and an outlet port 406 and is preferably constructed and arranged to fit in-line with an administration tube (e.g., tube 204 of FIG. 2) such that the fluid flowing in the tube to the patient also flows through sensor 402 .
  • an administration tube e.g., tube 204 of FIG. 2
  • flow rate sensor 402 comprises a positive displacement flow sensor.
  • Such sensors operate by allowing known volumes of fluid to be transferred during each rotation.
  • the particular flow sensor illustrated comprises a two inter-meshed gears/impellers 408 , 410 (sometimes referred to herein as rotors or rotating members).
  • each impeller has six lobes, but other sizes and shapes may be used.
  • the impellers are held on pins within a housing 412 .
  • the housing is preferably sized and shaped for being used in-line with an administration tube (e.g., tube 204 of FIG. 2).
  • the flow sensor comprises four components: the first impeller 408 ; the second impeller 410 ; the housing (including the pins on which the impellers are mounted and rotate); and a cover 416 sized and shaped for sealing the unit such that entry and exit must be had via inlet 404 and outlet 406 , respectively.
  • the cover, housing, and impellers are also preferably sized and shaped such that substantially all fluid passing through the sensor passes by operation of first and second impellers 408 and 410 in a positive displacement fashion.
  • the cover 416 may be clear so that the operation of the sensor may be monitored by an optical reader. If the flow sensor 402 is constructed primarily out of a silicon or silicon-based material, cover 416 preferably comprises a flat, clear, and heat resistant material, such as, for example Pyrex®. If flow sensor 402 is constructed primarily out of plastic, a flat plastic cover may be used. Laser welding techniques or ultrasonic welding may be used to seal the cap to the base. Preferably, in ultrasonic welding applications, energy directors are also used.
  • the alignment pins that hold the impellers in place could be part of the cap and/or the base.
  • the base and/or cap could include recessed holes to accept pins that are part of the impellers (i.e., the impellers have pins that extrude from their top or bottom).
  • flowing fluid causes impellers 408 , 410 to rotate and to transfer a known volume of fluid from the input port 404 side to the outlet port 406 side.
  • Optical or other techniques are used to count rotations (or partial rotations). Such information is indicative of flow rate because each rotation relates to a known volume of fluid. Therefore, flow rate sensor 402 effectively provides a flow rate signal that is indicative of an actual rate of fluid flow through the sensor.
  • One method of providing an optical indication is to mark one or more of the lobes of one or both impellers 408 , 410 such that an optical contrast is created.
  • An optical reader then optically detects when the marked lobe has moved, thereby providing an indication of a rotation.
  • the reader may be configured to illuminate flow rate sensor 402 (e.g., using an LED) and to thereafter examine the light reflected to detect the output signal (e.g., flow rate signal from flow rate sensor 212 in FIG. 2).
  • the flow sensor itself is preferably passive; the reader supplies the light and processes the returned light to provide a signal to the controller.
  • a controller (e.g., controller 232 ) can use this information to determine an actual flow rate through flow rate sensor 402 . This is so because each rotation of the impellers results in a known volume of fluid passing through the impellers.
  • an impeller can include a magnetic component that generates a detectable magnetic field that changes as the impeller rotates (e.g., an electrical variation caused by the rotation of the impeller).
  • a magnetic component that generates a detectable magnetic field that changes as the impeller rotates (e.g., an electrical variation caused by the rotation of the impeller).
  • Such a changing magnetic field would provide a flow rate signal that could be detected by, for example, a Hall sensor or similar device.
  • the reader may be made integral with the flow rate sensor itself.
  • a semiconductor device e.g., a semiconductor that forms or is part of the cap. The rotation rate is detected electronically by the semiconductor device and the output signal is provided directly to the controller, without the use of a reader that is separate from the flow rate sensor.
  • flow rate sensor 402 is constructed using relatively low-cost, precision MEMS and/or micro-molding techniques so that the sensor can be used in connection with a cost-effective, disposable administration set suitable for use in delivering a medical fluid.
  • the components that do not come directly into contact with the fluid and/or patient e.g., the pump, controller, and so on
  • the administration set and infusion pump are both designed to be disposable (e.g., disposed after each use). Two exemplary manufacturing techniques are discussed in greater detail below.
  • flow rate sensor 402 is provided for exemplary purposes.
  • other configurations of positive displacement flow sensors may use a different number of lobes and/or impellers, or have impellers of varying sizes and shapes—including asymmetrical impellers.
  • FIGS. 5 and 6 illustrate two exemplary methods of manufacturing a flow sensor, such as flow rate sensor 402 , suitable for use in connection with aspects of the present invention. More particularly, FIG. 5 illustrates the pertinent steps of manufacturing a positive displacement flow sensor using a high aspect ratio lithographic process which is sometimes referred to herein as ultra-violet LIGA (UV LIGA) or deep ultra-violet LIGA (DUV LIGA). FIG. 6 illustrates the pertinent steps of manufacturing a positive displacement flow sensor using a deep reactive ion etching sequence (deep RIE).
  • UV LIGA ultra-violet LIGA
  • DUV LIGA deep ultra-violet LIGA
  • FIG. 6 illustrates the pertinent steps of manufacturing a positive displacement flow sensor using a deep reactive ion etching sequence (deep RIE).
  • UV LIGA typically results in plastic parts. Deep RIE uses silicon or silicon carbide. Thus, the materials base for each approach differs. Further, both processes may be used to manufacture parts. The UV LIGA approach, however, may be more advantageously practiced if it is used to create replication masters that are used as molds or mold inserts.
  • the UV LIGA approach comprises four steps 502 , 504 , 506 , and 508 .
  • Step 502 involves preparation and exposure.
  • Step 504 involves developing.
  • Step 506 involves electroplating.
  • Step 508 involves removing any remaining photoresist.
  • a mask 510 (e.g., a quartz glass mask with chrome patterns) is placed above a workpiece to be exposed.
  • the workpiece to be exposed comprises a substrate layer 512 (e.g., a silicon wafer).
  • a seed layer 514 is attached to the substrate 512 by a deposition process.
  • a photoimageable material such as an epoxy-based negative photoresist layer 516 (e.g., SU-8) is added on top of substrate 512 (e.g., deposited from a bottle and spin coated).
  • the mask 510 comprises a two-dimensional pattern that is subsequently transferred down to the SU-8 layer.
  • the seed layer 514 is typically nickel, gold, copper, or nickel-ferrite (NiFe).
  • Flash layer below seed layer 514 there may also be a “flash” or very thin layer of a refractory metal such as chromium, titanium, or tantalum to act as an adhesion layer.
  • a refractory metal such as chromium, titanium, or tantalum
  • the flash layer is on the order of 50-500A, and the seed layer is about 400 -5000A. Additional information regarding this process may be found at chapter 5 of the “Handbook of Microlithography, Micromachining, and Microfabrication, Volume 2 Micromachining and Microfabrication,” available from SPIE Press 1997.
  • the photoresist layer is selectively exposed to deep UV radiation through the pattern of mask 510 .
  • the exposed photoresist layer 516 is developed.
  • the developing solution is a solvent and generally depends on the photoresist being used and whether the photoresist is a positive or negative tone.
  • This development process removes the portions of photoresist layer 516 that were exposed to the UV radiation, leaving structures 530 and 532 .
  • the remaining structure is electroplated (up from seed layer 514 ), filling the exposed portions 536 removed during the development process.
  • the remaining portions of the photoresist e.g., structures 530 , 532
  • electroplated structures 540 could be simultaneously formed.
  • one structure could correspond to an impeller (e.g., impeller 408 of FIG. 4A), and another structure could correspond to a housing (e.g., housing 412 of FIGS. 4A and 4B).
  • impeller e.g., impeller 408 of FIG. 4A
  • housing e.g., housing 412 of FIGS. 4A and 4B
  • These structures could thereafter be assembled to form a flow sensor of an appropriate size and shape for use in connection with, for example, the various methods and systems described herein.
  • structures can be formed for a flow sensor housing having an inlet port and an outlet port, and having pins for accepting first and second impellers.
  • a clear plastic cover is bonded to the top of the housing, thereby ensuring that substantially all fluid flowing into the flow sensor through the inlet port exits the sensor through the outlet port.
  • the micro-fabrication processes described herein can be used for creating molds or mold inserts (e.g., negative images of the desired structures).
  • molds or mold inserts e.g., negative images of the desired structures.
  • One advantage of such a micro-molding approach is that a large number of molds can be made at once, thereby allowing for large-scale production of flow sensor components, without the need for using the UV LIGA process other than for creating the mold.
  • components may be made of a plastic or similar material that is suitable for use in a medical environment (e.g., disposable).
  • numerous thermoplastic materials could be used (e.g., polycarbonate or liquid crystal polymer) to mold flow sensors from the master.
  • UV-LIGA One advantage of using UV-LIGA is that it does not require the use of an expensive synchrotron radiation source. As mentioned above, there are relatively few synchrotrons in the world. In contrast, UV sources are more readily available and relatively inexpensive, and masters can be created in most moderately equipped semiconductor clean room environments.
  • deep RIE is a silicon-based process in which deep reactive ion etching is applied to selectively etch away silicon material from the workpiece.
  • the selectivity of the etching process is determined by photolithographic techniques, such as those developed for manufacturing integrated circuits.
  • deep RIE provides good verticality, allowing 3-dimension structures to be established from 2-dimension patterns.
  • Deep RIE provides a suitable process for manufacturing flow sensors (either directly or by manufacturing micro-molds) for use in connection with a closed-loop flow control system and method, in accordance with aspects of the invention.
  • One such flow sensor may be created by etching silicon impellers from one substrate, and etching an accepting housing from another substrate (or from another part of a single substrate).
  • the housing preferably includes alignment pins positioned for accepting the impeller gears so that a positive displacement arrangement is formed.
  • the housing also preferably includes a base having a landing. The impeller gears are then placed on their respective rotation pins (either manually or by an automated process).
  • a coverslip e.g., a clear, heat resistant cover material such as Pyrex®
  • All or part of the impellers and/or base surface may be oxidized to produce a desired optical contrast between the respective surfaces. This optical contrast can be used for sensing rotation of the impellers.
  • FIG. 6 illustrates pertinent steps of producing an impeller and a housing for a flow sensor.
  • a workpiece is prepared comprising a silicon substrate 612 bonded to a base layer 614 .
  • the base layer 614 may comprise any number of materials.
  • base layer 614 comprises another silicon wafer.
  • photoresist may be used as an adhesive layer.
  • Other substrate materials may be used such as, for example, silicon carbide.
  • a photoresist material 616 is applied on the silicon substrate and then patterned using exposure and development steps. Thus, the photoresist is developed to form a 2-dimensional mask pattern so that etching selectively occurs only where desirable to create the part being produced.
  • This pattern is thereafter transferred down into the base layer (e.g., silicon) using reactive ion etching.
  • the base layer e.g., silicon
  • reactive ion etching Many commonly available photoresist materials are suitable. It should be understood that the 2-dimensional mask pattern could be transferred to an alternate layer, such as a silicon nitride or silicon oxide layer.
  • a deposited metal could serve as the etch mask.
  • a metallic etch mask would be useful in fabricating relatively tall structures by reactive ion etching techniques.
  • the base layer e.g., silicon
  • the photoresist layer may be etched at a higher rate than the photoresist layer is being etched (e.g., perhaps 100 times greater).
  • a photoresist mask may be rendered effective if the etching process is carried out extensively to fabricate tall structures (e.g., several hundred microns deep).
  • a metallic etch mask (etched even more selectively than a photoresist) would be useful.
  • the photoresist 616 has a 2-dimension shape corresponding to the 3-dimension part being produced.
  • the photoresist has a 2-dimension shape like that of the desired impeller.
  • the workpiece is selectively exposed and developed so that the exposed silicon is etched away, leaving the base layer, a silicon structure of the desired height and shape, and the photoresist (see 604 ). Thereafter, the photoresist is stripped away, leaving the base layer and the silicon structure (see 606 ). Finally, the structure is released from the base layer (see 608 ).
  • a flow sensor e.g., a positive displacement flow sensor
  • the silicon parts are coated with a relatively harder material (e.g., silicon nitride, carbon, or diamond) before the sensor is assembled.
  • Silicon is a hard, but brittle material. As such, a coating improves the strength and integrity of the parts.
  • deep RIE can be used to fabricate molds for micro-molding flow sensors in a relatively low-cost, high-volume manner.
  • a micro-molded or micro-fabricated flow sensor (e.g., a positive displacement flow sensor) is sized and shaped for being placed in-line with an administration tube (e.g., tube 204 ) as part of a disposable administration set.
  • an administration tube e.g., tube 204
  • such a flow sensor is integrated into an infusion set in which the fluid supply, the pump, the administration tube, the flow sensor, the controller and the reader are all part of a disposable unit.
  • UV LIGA and/or deep RIE are believed to be two preferred methods for manufacturing flow sensors (or molds therefor)
  • other micro-fabrication techniques may be substituted. These techniques include, for example, synchrotron LIGA and techniques that are not yet available for exploitation.
  • FIG. 7 is a top view of a cap piece 700 , suitable for use in connection with a positive displacement flow rate sensor, in accordance with aspects of the present invention.
  • a positive displacement flow sensor e.g., sensor 402 of FIGS. 4A and 4B
  • optically measuring the rotation of the impellers lobes For example, a small optical spot is used to mark one of the lobes. A reader detects when the marked lobe passes a given point and can thereby detect the rotation rate of the impeller. Because the flow rate sensor is a positive displacement-type sensor, knowledge of the rotation rate corresponds to the actual flow rate.
  • a similar technique involves a detector focused down, into the sensor, that looks for a reflection due to an optical contrast between the base and impeller. If the base is dark and the impeller is relatively light in contrast to the base, most of the reflected light will occur when a lobe passes. Such an approach generally allows a faster detection rate than monitoring a marked lob.
  • FIG. 7 illustrates an alternative to using an optical spot.
  • the cap piece 700 has imposed thereupon a pattern 702 that replicates one position of the two impellers relative to each other.
  • pattern 702 is applied to cap piece 700 with additive processes or subtractive processes, creating a roughened surface.
  • the pattern 702 is selected to provide an optical contrast between pattern 702 and the impellers 704 . For example, if the impellers are a shade of white, the imposed pattern 702 is a dark shade.
  • a relatively broad light source is applied from above to illuminate the flow sensor. Light is reflected back from the relatively light impeller lobes when the impellers are exposed from behind pattern 702 .
  • the amount of light reflected back varies as a function of the amount of the impeller 704 that is exposed from under pattern 702 .
  • reflection intensity will rise and fall to denote each partial rotation associated with a lobe.
  • the reflected light intensity will increase/decrease at a known number of cycles per revolution, depending upon the number of lobes, thereby providing an indication of the rotation rate of the sensor.
  • flow sensors having a “dual layer” nature can be fabricated (e.g., impellers having pins on the bottom).
  • impellers having pins fabricated on the bottom can be fabricated using DUV LIGA by adding another layer (i.e., another SU-layer after step 506 ), and thereafter, exposing, developing, and electroplating.
  • machining can be used in connection with DUV LIGA processing to fabricate features of a mold that are not dimensionally critical. Such features may include, in some embodiments, input and output ports of a positive displacement flow sensor.
  • a silicon package e.g., the silicon components and cover slip
  • Such a plastic housing can include, for example, input and output ports. Other variations are possible.

Abstract

A fluid delivery system having a closed-loop control process for delivering a medical fluid to a patient. A fluid infusion system includes a pump for delivering a fluid to a patient via an administration tube. A flow sensor associated with the administration tube provides an indication of the actual flow rate of fluid in the administration tube. Such a flow sensor may comprise a positive displacement flow sensor constructed using micro-fabrication and/or micro-molding techniques. A reader reads the actual flow rate signal and provides an indication to a controller for controlling the pump. The flow rate information can also be used for providing status information, such as the existence of a blockage in the fluid delivery system.

Description

    BACKGROUND OF THE INVENTION
  • 1. Field of the Invention [0001]
  • The invention relates generally to delivering fluids to a patient and, particularly, to closed-loop flow control systems and methods for delivering medical fluids to a patient at a controlled delivery rate. [0002]
  • 2. Description of the Prior Art [0003]
  • A variety of fluid delivery systems are currently being used in the medical field for delivering medical fluids (containing medication, nutrition, saline, and so on) to human and veterinary patients. It is often desirable to administer such medical fluids at relatively precise delivery rates. In some cases, the rate of delivery may be exceptionally important. In recent years, it has also been found to be advantageous to use various types of infusion pumps to administer medical fluids automatically, over extended periods of time. A typical infusion pump delivers the medical fluid into the patient's venous system using a delivery channel which usually comprises an administration tube (e.g., a polyvinyl chloride tube) connected to the patient using some form of catheter, needle, or the like. [0004]
  • Heretofore, infusion pumps and similar devices known in the art have typically not provided closed-loop flow control to achieve precise delivery rates. Rather, flow control has been open loop because actual flow rate information has not been used in controlling the infusion pump. A typical accuracy of such systems, in terms of flow rate, is normally no better than about +/−5%, and requires relatively sophisticated (and costly) mechanical components and tight material/geometry controls (e.g., of the tubing) to achieve that rate. In fact, ambulatory pumps typically achieve accuracies of +/−6-8%. Further, non-ambulatory pumps often do not achieve a five percent accuracy range at low flow rates or over longer time periods due to modification of the tubing material over time. For example, a typical peristaltic type pump requires repeated deformation of the administration tube. This deformation process changes the elastic recovery properties of the tube, resulting in changes in the volumetric output of the pump over time. One volumetric pump available from the assignee of the present application has a specified rating of +/−5% at 1-1200 ml/hr and +/−10% at 0.1-1 ml/hr. Another pump available from the assignee of the present application has a rated accuracy of +/−5% for the first 24 hours of use and +/−10% thereafter. [0005]
  • While the foregoing accuracy ranges may be acceptable for some uses, greater accuracy is desirable for other uses. In some prior art systems, the pumping mechanism associated with the infusion pump is monitored and controlled, but the actual flow of fluid in the administration tube is not. For example, commonly assigned U.S. Pat. No. 5,533,981 describes a syringe infusion pump having a sensor for detecting the position and capture of a syringe plunger for use in controlling the dispensing of fluid from the syringe. Commonly assigned U.S. Pat. No. 6,078,273 discloses a variety of known infusion pump systems such as, for example, roller pump systems, peristaltic-type systems, valve-type systems, and motor driven systems. Further, commonly assigned U.S. Pat. No. 5,482,841 discloses a volumetric-type infusion pump. An example of an ambulatory infusion pump is a pump sold under the mark IPUMP by the assignee of the present application. An example of an ambulatory pump may also be found in U.S. Pat. No. 5,993,420. [0006]
  • Some systems have attempted to provide closed-loop control. For example, commonly assigned U.S. Pat. No. 5,533,412 discloses a pulsed thermal flow sensor. In such a system, the fluid is heated by a pulsed heating element. The fluid carries the thermal pulse through a flow channel to two sensor elements spaced apart, downstream from the heating element. The transit time of the thermal pulse between the two sensor elements provides an indication of the fluid flow velocity. Thus, such an approach requires the application of a heat pulse to the fluid in order to determine flow rate information. [0007]
  • Other prior art systems use information generated by positional encoders and decoders associated with a motor shaft to control an infusion pump. For example, the above-mentioned U.S. Pat. No. 6,078,273 discloses an encoder/decoder for use in controlling a medical infusion pump. While such systems reflect improvements in the art, they do not control fluid delivery in view of actual flow rates. In some circumstances, therefore, such systems would not provide as accurate information and tight control based on actual fluid flow rate data. [0008]
  • Sensors, such as positive displacement (PD) flow rate sensors, have been in use for many years and directly detect flow rates. A typical PD sensor includes two complementary rotating elements that, when exposed to a fluid flow, allow a relatively well-defined volume of the fluid to transfer from one side of the sensor to another side of the sensor with each rotation (or partial rotation) of the rotating elements. One advantage of PD sensors is that they support a variety of fluids with substantially equal levels of accuracy. In the prior art, such devices typically measure large fluid flow rates and the requisite level of precision is achieved by conventional precision machining and polishing techniques. In fact, components must sometimes be matched to ensure minimal clearances of the rotating elements and inner housing geometry. Such conventional PD sensors, however, are not well-suited for use in high-precision medical fluid delivery systems. For example, a commercial infusion pump may require the ability to deliver fluids over a wide range of delivery rates (e.g., 4 logs), including very low flow rates. Moreover, conventional manufacturing techniques tend to be expensive and, therefore, are not well-suited for use in manufacturing disposable items. [0009]
  • In recent years, fabrication techniques have developed that allow for the manufacture of micro-fabricated devices. Some of such devices are referred to as micro electromechanical system (MEMS) devices and micro molded devices. One technique for fabricating such devices is referred to in the art as LIGA processing. LIGA (Lithographie Galvanoformung Abormung) was developed in Germany in the late 1980s and translates roughly to the steps of lithography, electroplating, and replication. LIGA allows for the formation of relatively small, high aspect ratio components. Using this technique, a photoresist layer (e.g., an acrylic polymer such as polymethyl methacrylate (PMMA)) is applied to a metallized substrate material. The photoresist layer is selectively exposed to synchrotron radiation (high-energy X-ray radiation) via a mask pattern to form the desired high aspect ratio walls. Thus, the radiation “unzips” the PMMA backbone. The exposed sample is thereafter placed in a developing solution that selectively removes the exposed areas of PMMA. One development solution is 20% by volume of [0010] tetrahydro 1,4-oxazine, 5% by volume 2-aminoethanol-1, 60% by volume 2-(2-butoxyethoxy)ethanol, and 15% by volume water. The sample is thereafter electroplated; metal fills the gaps within the PMMA to form a negative image. The PMMA is then removed using a solvent, leaving a metal form for either immediate use or for use as a replication master. The entire LIGA process is described in greater detail in chapter 6, page 341 of Marc Madou, “The Fundamentals of Microfabrication, the Science of Miniaturization,” Second Edition (CRC Press 2001).
  • LIGA has been identified for use in manufacturing micro-fabricated fluid pumps. It is believed, however, that LIGA-based micropumps have never been made available commercially. Cost is one substantial drawback of LIGA; it is believed that there are relatively few synchrotron devices (e.g., 10-15 devices) in the world. Accordingly, LIGA is fairly limited in its applicability for directly manufacturing low cost devices. [0011]
  • In view of the foregoing, an improved system and method for delivering a fluid to a patient is desired. [0012]
  • SUMMARY OF THE INVENTION
  • In one form, an improved fluid delivery system benefits from a closed-loop control process that uses flow rate information to ensure that the desired flow rate is substantially achieved. Further, in one form, such a system is constructed using one or more micro-fabrication and/or molding techniques allowing for a cost-effective, disposable administration set. [0013]
  • Briefly described, a system for delivering fluid at a desired flow rate from a reservoir to a delivery point associated with a patient, embodying aspects of the invention, includes a delivery channel between the reservoir and the delivery point through which the fluid is delivered to the patient. A pump is associated with the delivery channel for operatively delivering the fluid to the delivery point at an adjustable output rate. A flow sensor is located along the delivery channel for sensing a flow of the fluid in the delivery channel and for generating a flow rate signal indicative of a rate of flow of the fluid in the delivery channel. The flow sensor comprises a positive displacement flow sensor. A controller controls the pump. The controller causes adjustments to the output rate of the pump as a function of the flow rate signal whereby the desired flow rate is substantially achieved. [0014]
  • In another aspect, the invention relates to a closed-loop fluid delivery system for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube. The closed-loop fluid delivery system includes fluid delivery means located along the administration tube for operatively supplying the fluid to the delivery point at a controllable output rate. A positive displacement flow sensing means is located between the fluid delivery means and the delivery point for sensing an actual flow rate of the fluid in the delivery channel and for generating a flow rate signal indicative of the actual flow rate of the fluid in the delivery channel. A control means associated with the fluid delivery means receives and is responsive to the flow rate signal for adjusting the output rate of the fluid delivery means such that the desired delivery rate at which the fluid is supplied to the delivery point associated with the patient is substantially achieved. [0015]
  • In still another aspect, the invention relates to a system for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube. The system includes a delivery mechanism operatively connected between the reservoir and the delivery point. The delivery mechanism is constructed and arranged for selectively delivering the fluid to the delivery point via the administration tube at a controllable output flow rate. A closed-loop control system controls the output flow rate of the delivery mechanism. The closed-loop control system includes a positive displacement flow sensor connected in-line with the administration tube for determining an actual flow rate of the fluid in the administration tube and for providing an flow rate indication reflecting the actual flow rate. A reader associated with the positive displacement flow sensor receives the flow rate indication and provides a flow control signal reflecting the flow rate indication. A controller associated with the delivery mechanism receives and is responsive to the flow control signal for controlling the output flow rate of the delivery mechanism as a function of the flow control signal such that the output flow rate is substantially equal to the desired delivery rate. [0016]
  • In yet another aspect, the invention relates to a method of delivering a medical fluid to a delivery point associated with a patient at a desired delivery flow rate. The method includes operatively connecting a reservoir to a delivery mechanism. The reservoir contains the medical fluid to be delivered to the delivery point. The delivery mechanism is operatively connected to an administration tube. The administration tube is in fluid communication with the delivery point. The delivery mechanism receives the medical fluid from the reservoir and supplies the medical fluid to the delivery point via the administration tube at an output flow rate. The output flow rate of the medical fluid in the administration tube is sensed using a positive displacement flow sensor. The sensed output flow rate of the medical fluid is compared with the desired delivery flow rate. The delivery mechanism is controlled such that the output flow rate substantially corresponds to the desired delivery flow rate. [0017]
  • In another aspect, the invention relates to a closed-loop flow control system for controlling a medical fluid delivery system. The medical fluid delivery system delivers a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube. The medical fluid delivery system includes a delivery mechanism operatively connected between the reservoir and the delivery point. The delivery mechanism is constructed and arranged for delivering the fluid to the delivery point via the administration tube at a controllable output flow rate. The closed-loop flow control system includes a positive displacement flow sensor connected in-line with the administration tube for determining an actual flow rate of the fluid in the administration tube and for providing an flow rate indication reflecting the actual flow rate. A reader associated with the positive displacement flow sensor receives the flow rate indication and provides a flow control signal reflecting the flow rate indication. A controller associated with the delivery mechanism receives and is responsive to the flow control signal for controlling the output flow rate of the delivery mechanism as a function of the flow control signal such that the output flow rate is substantially equal to the desired delivery rate. [0018]
  • In still another aspect, the invention relates to a method of detecting a blockage in a medical fluid delivery system arranged for delivering a medical fluid to a delivery point associated with a patient at a desired flow rate. The method includes operatively connecting a reservoir to a delivery mechanism. The reservoir contains the medical fluid to be delivered to the delivery point. The delivery mechanism is operatively connected to an administration tube that is in fluid communication with the delivery point. The delivery mechanism receives the medical fluid from the reservoir and supplies the medical fluid to the delivery point via the administration tube at an output flow rate. The output flow rate of the medical fluid in the administration tube is sensed. A determination is made whether the sensed output flow rate is indicative of a blockage in the administration tube. An alarm signal is provided if it is determined that the sensed output flow rate indicates that the administration tube is blocked. [0019]
  • In yet another aspect, the invention relates to an administration set for use in connection with a fluid delivery system that is arranged for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate. The fluid delivery system includes a pump having an output rate for delivering fluid from the reservoir to the delivery point and a controller for adjusting the output rate of the pump such that the desired delivery rate is substantially achieved. The administration set includes an administration tube for providing fluid communication between the reservoir and the delivery point. A positive displacement flow sensor is located along the administration tube and is sized and shaped for being positioned in fluid communication with the fluid within the administration tube. The positive displacement flow sensor senses a rate of flow of the fluid in the administration tube and generates a flow rate signal that is indicative of the sensed rate of flow of the fluid in the administration tube such that the controller adjusts the output rate of the pump as a function of the flow rate signal. [0020]
  • In another form, the invention relates to a positive displacement flow sensor for use in connection with a medical fluid infusion system that includes an administration set having an administration tube. The positive displacement flow sensor comprises a housing having an inlet port and an outlet port. The inlet and outlet ports are operatively connected to the administration tube. A first rotor is positioned within the housing between the inlet port and the outlet port. A second rotor is positioned within the housing between the inlet port and the outlet port. The second rotor is positioned adjacent to the first rotor, and the first and second rotors are constructed and arranged to rotate in response to a flow of medical fluid in the administration tube for detecting flow of the medical fluid in the administration tube. A cover encloses the housing such that when the medical fluid flows into the inlet port it causes the first rotor to rotate and thereafter the medical fluid exits through the outlet port. [0021]
  • Alternatively, the invention may comprise various other devices, methods, and systems. [0022]
  • Other objects and features will be in part apparent and in part pointed out hereinafter.[0023]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 illustrates one embodiment of an infusion pump suitable for use in connection with aspects of the invention. [0024]
  • FIG. 2 is a block diagram of one embodiment of a closed-loop flow control system suitable for use in connection with an medical fluid infusion pump, such as the infusion pump of FIG. 1, according to aspects of the invention. [0025]
  • FIG. 3A is a flow chart that illustrates an exemplary method of delivering a fluid to a patient in accordance with a closed-loop flow control process, suitable for use in connection with aspects of the invention. [0026]
  • FIG. 3B is a flow chart that illustrates an exemplary method of detecting and reporting a blockage/occlusion in an infusion system, in accordance with aspects of the invention. [0027]
  • FIG. 4A is a schematic representation of a top view of one embodiment of a flow sensor suitable for use in connection with a closed-loop flow control system, such as the system of FIG. 2. [0028]
  • FIG. 4B is a schematic representation of a side view of one embodiment of a flow sensor suitable for use in connection with a closed-loop flow control system, such as the system of in FIG. 2. [0029]
  • FIG. 5 illustrates an exemplary process of manufacturing a positive displacement flow sensor using a high aspect ratio lithographic process. [0030]
  • FIG. 6 illustrates an exemplary process of manufacturing a positive displacement flow sensor using a deep reactive ion etching sequence. [0031]
  • FIG. 7 is a top view of a cap piece, suitable for use in connection with a positive displacement flow rate sensor, in accordance with aspects of the present invention.[0032]
  • Corresponding reference characters indicate corresponding parts throughout the drawings. [0033]
  • DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
  • Referring now to the drawings, FIG. 1 illustrates one embodiment of an [0034] infusion pump 100 suitable for use in connection with aspects of the present invention. In the illustrated example, the infusion pump 100 comprises a syringe-type infusion pump. Infusion pump 100 includes a housing 102, a display screen 104, and a control panel 106. The control panel 106 and the display screen are used to enter set-point data for operating infusion pump 100 and for monitoring the operation of pump 100.
  • The [0035] infusion pump 100 also includes a syringe barrel 108 for holding a medical fluid to be administered. A barrel bracket 110 attaches the syringe barrel 108 is attached to the housing 102. A movable syringe driver 112 is also attached to housing 102 and is positioned in engagement with a syringe plunger 114. A driving mechanism within housing 102 is constructed and arranged so that the movable syringe driver 112 can drive syringe plunger 114 into (or out of) syringe barrel 108 in a controlled direction along barrel 108.
  • Operationally, a user loads a desired amount of the fluid to be administered into [0036] syringe barrel 108. Syringe barrel 108 is mounted to housing 102 via bracket 110 and plunger 114 is moved into position within barrel 108. Infusion pump 100 is attached to a patient 120 (e.g., a human patient or a veterinary patient) via a channel such as an intravenous PVC administration tube 122. The user enters the desired administration program on control panel 106 and infusion pump 100 controls a movement of plunger 114 via driver 112 to deliver the fluid to the patient at a programmed delivery rate corresponding to the administration program.
  • To this point, the description of [0037] infusion pump 100 and its operation in connection with patient 120 has been generally in accordance with known infusion systems. In other words, fluid delivery is controlled in an open-loop fashion-based on a desired set point without regard to actual flow rates. Line 124 diagramatically illustrates a closed-loop information feedback path from a flow rate sensor 126 that is positioned for detecting a flow rate in tube 122 at a point between infusion pump 100 and patient 120. Closed loop control using such flow information in a feedback path is discussed in greater detail in connection with FIG. 2. Also, and as also discussed in greater detail below, aspects of a sensed flow information feedback system can be used for occlusion detection instead of or in addition to flow rate control.
  • FIG. 2 is a block diagram that schematically illustrates one embodiment of a closed-loop flow control system suitable for use in connection with an medical fluid infusion pump, such as a volumetric or ambulatory type pump. It should be understood that a syringe pump does not “draw” from a reservoir. Rather, as shown in FIG. 1, the plunger of a syringe pump acts upon the reservoir to output fluid to the patient. For present purposes, such differences between a syringe type pumps and volumetric and ambulatory type pumps are not substantial, and aspects of the invention may be employed with each of these types of infusion pumps. [0038]
  • In particular, FIG. 2 illustrates a [0039] fluid reservoir 202 connected to an administration tube 204. Arrows 206 indicate that a fluid flows in the administration tube 204 into the patient. Administration tube 204 is operatively connected to an infusion pump system 208 that is positioned along the administration tube 204. It should be understood that the position of the infusion pump system 208 and the nature and type of connection between infusion pump 208 and administration tube 204 will often depend, at least in part, on the particular type of infusion pump used. In the illustrated embodiment, infusion pump 208 includes a pumping delivery mechanism 210. As will be explained in more detail below, there are a variety of pumping mechanisms that may be employed. For example, the pumping mechanism 210 may comprise a syringe driver driving a syringe plunger in a syringe-type infusion pump. For present purposes, it is sufficient to note that the pumping mechanism 210 is controllable/adjustable for controlling/adjusting a flow rate of the fluid within administration tube 204 to conform with a desired flow rate.
  • A [0040] flow rate sensor 212 is located in-line with administration tube 204 and receives the fluid through pumping mechanism 210. The flow rate sensor 212 preferably includes an inlet port 214 and an outlet port 216. The inlet port 214 receives flowing fluid at the flow rate provided by pumping mechanism 210 and provides flowing fluid at its output port 216. In one embodiment, administration tube 204 comprises a plurality of IV tube pieces. A first piece of IV tube connects pumping mechanism 210 to input port 214 and a second piece of IV tube connects output port 216 to a delivery point associated with a patient 220. Other flow sensing arrangements are possible. For example, flow rate sensor 212 could be located entirely within the IV tube.
  • It should be understood that, in a typical continuous infusion pump, fluid runs from a reservoir to an access device through an administration set, flow rate may be measured at any convenient point along the path because the flow rate is the same—upstream or downstream of the pump. For example, the flow rate in [0041] administration tube 204 of FIG. 2 just below fluid reservoir 202 is equal to the flow rate at input port 214, as well as at output port 216. Some infusion pumps (e.g., metering and discontinuous systems), however, fill a defined volume of fluid from a reservoir, and thereafter pump that fluid out, over time, according to the delivery profile. Further, an amount of compliance may exist within a disposable administration set. Therefore, in many applications there will be value in locating the flow rate sensor downstream of the pump, and closer to the patient.
  • In one embodiment, [0042] fluid reservoir 202, tube 204 and flow rate sensor 212 comprise part of a disposable administration set that is mounted in infusion pump system 208. It should be understood that a disposable set could include a variety of components including, for example, valves (e.g., normally closed valves), specialized pumping complements, and the like. Further, the set can include a reservoir; or the reservoir can be separate and integrated with the set through a spike or other connection.
  • The [0043] flow rate sensor 212 provides an indication of an actual rate of flow within administration tube 204. In one embodiment, flow rate sensor 212 is a positive displacement flow sensor for providing a flow rate signal 224 representing the actual flow rate of fluid flowing in administration tube 204. It is to be understood that there are a variety of ways that flow rate sensor 212 could provide the flow rate signal 224. For example, flow rate sensor 212 can be constructed such that a varying optical contrast or electrical signal is generated by the flow of fluid. Exemplary structures and methods for providing such a flow rate signal are discussed in greater detail below. Further, in one embodiment, flow rate sensor 212 comprises a passive device, having no electrical connections thereto.
  • A [0044] reader 230, such as an optical or electrical signal detector, is preferably positioned adjacent flow rate sensor 212 such that it can receive/detect flow rate signal 224. In turn, the reader 230 communicates the detected flow rate signal 224 to a controller 232 via a communication path. In particular, reader 230 receives flow rate signal 224 from flow rate sensor 212 and supplies a flow control signal 234 to the controller 232. It should be understood that the flow control signal 234 preferably provides substantially the same information as the flow rate signal 224—an indication of the actual flow rate of fluid in tube 204. For example, in one embodiment, the flow control signal 234 comprises one or more pulses. In such an embodiment, controller 232 is programmed to interpret each pulse as corresponding to a fixed volume of fluid flowing through sensor 216. Accordingly, controller 232 can determine the actual flow rate sensed in the administration tube as a function of the number of pulses received from reader 230. In such an embodiment, an indication of the cumulative flow volume delivered is provided by the number of pulses, and an indication of the instantaneous flow rate is determined by the time period of the pulses.
  • In one embodiment, the communication path between [0045] reader 230 and controller 232 comprises a wired communication channel 236. In another embodiment, the communication path comprises a wireless (e.g., IR, RF, and/or the like) communication channel 238. The wireless channel 238 may be advantageous, for instance, in systems in which flow rate sensor 212 and/or reader 230 are located at a distance from controller 232 and/or when physical connectivity is undesirable. One exemplary wireless communication channel uses Bluetooth™ wireless technology. Bluetooth™ is a wireless specification from a trade association, Bluetooth SIG, Inc. In general, it is a low cost and low power specification, operating in the unlicensed 2.4 GHz spectrum, and using spread spectrum frequency hopping techniques.
  • The [0046] controller 232 is operatively connected for automatically controlling pumping mechanism 210. This is illustrated schematically as a pump control signal 240 on line 242 between controller 232 and pump 210. It should be understood that a wide variety of devices may serve as controller 232. For example, controller 232 may be embodied by a processor (e.g., a microprocessor or microcontroller), discrete logic components, application specific circuitry, programmable logic devices, analog circuitry, or combinations thereof. Further, a motor-based pump could be controlled by adjusting the motor rotation rate or a cycle time associated with the motor. If a certain type of MEMS-based pump is employed, for example, control may be achieved by adjusting the frequency of a piezo oscillation.
  • The system can also be configured to provide a status signal. For example, [0047] controller 232 provides a status signal, such as an alarm signal 250, on a line 252 (and/or a wireless channel 256) to a status monitoring device 254. In one form, the status monitoring device 254 comprises an audible alarm system for providing an audible alarm in the event of a malfunction. Status monitoring device 254 may also comprise other audio, visual, audio-visual, and vibrating devices such as, for example, CRT monitors, pagers, horns, buzzers, speakers, computers, portable telephones (e.g, cellular telephones), personal digital assistants (PDAs), and the like. By way of one specific example, controller 232 provides an alarm signal to cause an audible and/or visual alarm to be activated if controller 232 is unable to control pump 210 to achieve a desired flow rate. Such a condition can occur if an occlusion or blockage in administration tube 204 prevents an adequate flow of fluid to patient 220. Such a blockage may include complete blockages, as well as partial blockages affecting flow rate. Alarm conditions can be programmed to occur for a variety of other reasons, such as when the fluid supply in reservoir 202 becomes depleted to a level at which pump 210 can no longer deliver the fluid at the desired delivery rate. It should be appreciated, however, that status indications other than failures or improper operational conditions may also be provided. For example, a status signal could be used to provide an indication at a remote monitoring station of the current sensed flow rate or another indication regarding the operation of the system. Similarly, sensed flow rate information can be used to anticipate when the fluid supply will be depleted, such that a suitable indication is provided in advance of such event.
  • An operational example of the closed-loop flow control system of FIG. 2 is now described. A patient is operatively connected to administration tube [0048] 204 (e.g., via a catheter inserted at a desired delivery point associated with the patient). Reservoir 202 contains a fluid to be administered to the patient and is operatively connected to administration tube 204 and pumping mechanism 210. A desired delivery rate is entered on a control panel associated with the pump (see, e.g., FIG. 1). In FIG. 1, for example, it is to be understood that control panel 106 and display 104 cooperate to provide a user interface to facilitate entering set-point data for use by pump 100. In the present embodiment, controller 232 uses set-point data representative of the desired delivery rate in combination with the flow control signal 234 for controlling the system.
  • As [0049] pump 210 causes the fluid to be delivered to patient 220 via tube 204, flow rate sensor 212 senses the flow rate of the fluid in tube 204 and periodically (or continuously) outputs flow rate signal 224 which is received/detected by reader 230. For example, if flow rate sensor 212 is constructed and arranged to provide an optical signal indication of the actual flow rate of fluid, reader 230 comprises an optical reader for detecting the optical signal indication generated by flow rate sensor 212. As a further example, in one embodiment reader 230 illuminates flow rate sensor 212 with a light and examines the light reflected by the flow rate sensor to determine the flow rate signal 224.
  • [0050] Reader 230 thereafter provides flow control signal 234 to controller 232. This flow control signal 234 is functionally related to the flow rate signal 224 and, therefore, provides an indication of the actual flow rate of fluid into patient 220. As such, controller 232 is able to monitor the actual flow rate of fluid in tube 204. With this information, controller 232 is able complete a closed-loop control path with pump 210. In other words, controller 232 executes a control scheme for generating the pump control signal 240 to adjust the pumping action of pump 210 so that the actual flow rate, as measured by flow rate sensor 212, more closely matches the desired flow rate. It should be understood that a variety of control schemes may be employed, depending upon goals. For example, in some applications it may be desirable to control the pump to provide a high degree of accuracy in terms of instantaneous flow rate. In other applications, it may be desirable to control the pump in terms of the total volume of fluid infused. In still other applications, it may be desirable to optimize control in terms of both instantaneous flow rate and total volume. Other variations are possible.
  • The degree of accuracy with respect to controlling flow rate can be varied, depending upon usage. For example, if gross accuracy (e.g., +/−15%) is acceptable, the closed-loop feedback control could be disabled in software (e.g., via a control panel input) or by eliminating [0051] flow rate sensor 212 from the administration set. Gross accuracy can also be achieved by adjusting control parameters, such as sample rates and so on. On the other hand, if a relatively high degree of accuracy is desired (e.g., +/−2%), the controller is preferably programmed/configured to tightly control the pumping action of pump 210. It should be appreciated, therefore, that an infusion pump system, embodying aspects of the invention can be reconfigured to accommodate a wide variety of needs, thereby improving the usefulness of such a system.
  • As explained above, such a closed-loop flow control system has been heretofore unknown in the art. Among the advantages of such a system is the ability to more closely control the flow of fluid to [0052] patient 220. In some situations, a particular precise flow rate is valuable. Further, flow rate sensor 212 is compatible with a wide variety of fluid delivery profiles, including constant profiles, pulsatile profiles, and other time-varying and non-uniform delivery profiles. With such profiles, including pulsatile flow profiles, the pump may need to ramp up and/or down from its running rate faster than with other delivery profiles. Thus, knowledge of actual flow rate helps to ensure tighter control of the profile. For example, controller 232 can monitor the actual flow rate in tube 204 (as detected by flow rate sensor 212) over time and control the pumping action of pump 210 to ensure that the actual flow rate conforms to the desired delivery profile. Moreover, closed-loop control allows infusion pumps to be manufactured with a greater degree of flexibility in terms of manufacturing tolerances and the like. In some prior art systems, delivery accuracy is attempted by tightly controlling the tolerances of the mechanical pumping components and mechanisms, which can be expensive. With flow rate feedback control according to aspects of the invention, on the other hand, infusion pumps can be made with less precise (and therefore less expensive) components and mechanisms, yet still achieve a high degree of accuracy in terms of fluid delivery rate control.
  • It should be further appreciated that the tubing would not need to be as precise and the integration of the pump and disposable components would be less dependent upon the materials used in the disposable components. For example, PVC tubing provides certain advantages in prior art systems, so the design of the infusion pump may need to be tailored to be compatible with such tubing. This type of engineering expense may be eliminated if PVC tubing is no longer necessary. [0053]
  • Further, knowing the actual rate of flow in [0054] tube 204 with a relatively high degree of precision also allows the system to provide a highly accurate and fast occlusion detection capability. It should be appreciated that a blockage—a complete blockage and/or a partial blockage—between the fluid reservoir and the delivery point can result in an unacceptably low rate of flow. Such blockages are sometimes referred to herein as occlusions but may be caused by a variety of conditions, including a kink in tube 204. Prior art attempts to detect occlusions rely on pressure sensing, which requires a relatively large change in the pressure in the tube to be detected. A disadvantage of pressure sensing is that it may take a long time for the pressure in the tubing to increase to a detectable level. This is especially true when delivering fluids at a relatively low delivery rate. For example, a blockage (e.g., a complete and/or partial blockage) associated with a 0.1 ml/hour delivery rate could take two hours or more to be detected with a typical prior art pump. Further, if the sensitivity of a pressure sensing system is increased to reduce response times, more false alarms are likely to be experienced.
  • In contrast, a closed-loop flow controller according to aspects of the present invention is able to rapidly detect blockages (complete and/or non-complete blockages, even at very low delivery rates) because [0055] flow rate sensor 212 detects an actual flow rate and does not require a pressure build up. One embodiment of flow rate sensor 212 is capable of providing accurate measurements (e.g., better than +/−5%) over four logs of range. For example, a pump using such a flow sensor supplies fluid from about 0.1 ml/hr up to about 2000 ml/hr. Thus, flow rate sensing and occlusion detection is possible at low flow rates, as well as at higher flow rates.
  • For convenience, the foregoing descriptions of FIGS. 1 and 2 have been generally provided in terms of embodiments comprising syringe-type infusion pumps and ambulatory and volumetric pumps. One type of prior art syringe pump is more fully described in commonly assigned U.S. Pat. No. 5,533,981. It should be understood that, with the benefit of the present disclosure, closed-loop control systems and methods may be adapted for use with other types of medical fluid delivery systems. Such systems include, for example, rotary and linear peristaltic-type pump systems, valve-type pump systems, piezoelectric pump systems, pressure-based pump systems, and various motor and/or valve driven systems. [0056]
  • A peristaltic-type pump manipulates the IV administration tube to achieve a desired flow rate. In one embodiment, a peristaltic-type pump employs an array of cams or similar devices that are angularly spaced from each other. The cams drive cam followers that are connected to pressure fingers. These elements cooperate to impart a linear wave motion on the pressure fingers to apply force to the IV tube. This force imparts motion to the fluid in the IV tube, thereby propelling the fluid. Other forms of peristaltic-type pumps use different pressure means such as, for example, rollers. [0057]
  • Some valve-type pumps employ pumping chambers and upstream and downstream valving (e.g., electronically controlled valves) to sequentially impart a propulsion force to the fluid to be delivered to the patient. It is also possible to use a valve in connection with a gravity-fed delivery system in which gravity provides the motivating force and one or more valves are used to control the flow rate. Piezoelectric pumps control pumping by varying the magnitude of an applied voltage step. Pressure-based pumps adjust flow rate by controlling the pressure applied to a fluid reservoir (sometimes called “bag squeezer” systems). [0058]
  • Further, the closed-loop control systems and methods described herein may be used in ambulatory infusion pump systems and volumetric infusion pump systems. It should also be understood that the components illustrated in FIG. 2 are grouped for convenience. For example, the [0059] status monitor device 254 could be made integral with the rest of the infusion pump system 208. Likewise, reservoir 202 could be integral with the pump unit or separate. For example, in a syringe pump, the barrel of the syringe acts as a reservoir, but is physically mounted to the infusion pump housing. In other words, with syringe pumps and pressure-based pumps, the reservoir is typically contained within the pump boundaries. With a volumetric or ambulatory pump, the reservoir is generally more external to the pump boundaries.
  • FIG. 3A is a flow chart that illustrates an exemplary method of delivering a fluid to a patient in accordance with a closed-loop flow control process. As illustrated therein, a fluid reservoir (e.g., a fluid bag) is connected to an infusion pump which, in turn, is connected to the patient ([0060] blocks 302, 304). After a desired delivery rate is selected (block 306), fluid delivery begins (block 308). Periodically (or continuously) the actual flow rate of fluid to a delivery point associated with the patient is sensed (block 310). For example, and as explained above, a positive displacement flow rate sensor located in-line between the patient and the pump can be used to sense actual fluid flow and provide a flow rate indication to a control device. The actual flow rate is compared to the desired delivery rate at block 312. If the actual flow rate is appreciably greater than desired (block 314), the infusion pump is adjusted such that its output rate is reduced (block 316), thereby reducing the actual delivery rate to more closely match the desired flow rate. If, however, the actual flow rate is appreciably less than the desired rate (block 318), the infusion pump is adjusted such that its output rate is increased (block 320), thereby increasing the actual delivery rate.
  • In one embodiment, the method also includes using a disposable administration set that includes, for example, an administration tube and an in-line flow rate sensor (e.g., [0061] tube 204 and flow rate sensor 212 of FIG. 2) such that, upon completing the fluid delivery process, the administration set is discarded.
  • FIG. 3B is a flow chart that illustrates an exemplary method of detecting and reporting a blockage/occlusion in an infusion system, in accordance with aspects of the invention. In the illustrated example, the process is similar in several aspects to the method illustrated in FIG. 3A. At [0062] block 330, however, the sensed actual flow rate is compared to an occlusion/blockage threshold reference. This threshold can be a predetermined value (e.g., a fixed number or a fixed percentage of the desired delivery rate), or a dynamically determined value (e.g., a time varying threshold). In the illustrated embodiment, if the sensed actual flow rate is less than the occlusion threshold, a blockage is declared and an alarm condition is triggered (blocks 332, 334). It should be understood, however, that more complicated comparisons can also be performed. For example, rather than comparing sensed flow rate information against a threshold flow rate value, a change in the sensed flow rate (e.g., a slope) can be determined. If the slope exceeds a slope threshold, a blockage is declared. Further, there may be certain infusion protocols in which zero flow is expected for extended periods of time. In such situations, the controller preferably accounts for this fact.
  • It should be appreciated that flow rate comparisons (e.g., block [0063] 314 or block 330) need not be referenced to a fixed value. Rather, other flow rate comparisons are possible. Such comparisons include comparing the flow rate to an acceptability range and/or a time varying reference. Further the reference to which the actual flow rate is compared may be programmed by the user or pre-existing and used in connection with an algorithm or treatment protocol.
  • FIGS. 4A and 4B are schematic representations of one embodiment of a [0064] flow rate sensor 402 suitable for use in connection with a closed-loop flow control system, such as the pump system 208 illustrated in FIG. 2. Flow rate sensor 402 preferably comprises a micro-fabricated MEMS device or a similar micro-molded device (e.g., an assembly of micro-molded components). Exemplary fabrication techniques for manufacturing such a flow sensor are discussed below. Flow rate sensor 402 has an inlet port 404 and an outlet port 406 and is preferably constructed and arranged to fit in-line with an administration tube (e.g., tube 204 of FIG. 2) such that the fluid flowing in the tube to the patient also flows through sensor 402.
  • In the illustrated embodiment, [0065] flow rate sensor 402 comprises a positive displacement flow sensor. In general, such sensors operate by allowing known volumes of fluid to be transferred during each rotation. The particular flow sensor illustrated comprises a two inter-meshed gears/impellers 408, 410 (sometimes referred to herein as rotors or rotating members). In the illustrated example, each impeller has six lobes, but other sizes and shapes may be used. As illustrated, the impellers are held on pins within a housing 412. The housing is preferably sized and shaped for being used in-line with an administration tube (e.g., tube 204 of FIG. 2). In one embodiment, the flow sensor comprises four components: the first impeller 408; the second impeller 410; the housing (including the pins on which the impellers are mounted and rotate); and a cover 416 sized and shaped for sealing the unit such that entry and exit must be had via inlet 404 and outlet 406, respectively. The cover, housing, and impellers are also preferably sized and shaped such that substantially all fluid passing through the sensor passes by operation of first and second impellers 408 and 410 in a positive displacement fashion.
  • The [0066] cover 416 may be clear so that the operation of the sensor may be monitored by an optical reader. If the flow sensor 402 is constructed primarily out of a silicon or silicon-based material, cover 416 preferably comprises a flat, clear, and heat resistant material, such as, for example Pyrex®. If flow sensor 402 is constructed primarily out of plastic, a flat plastic cover may be used. Laser welding techniques or ultrasonic welding may be used to seal the cap to the base. Preferably, in ultrasonic welding applications, energy directors are also used.
  • By way of further example, the alignment pins that hold the impellers in place could be part of the cap and/or the base. Further, the base and/or cap could include recessed holes to accept pins that are part of the impellers (i.e., the impellers have pins that extrude from their top or bottom). [0067]
  • In operation, flowing fluid causes [0068] impellers 408, 410 to rotate and to transfer a known volume of fluid from the input port 404 side to the outlet port 406 side. Optical or other techniques are used to count rotations (or partial rotations). Such information is indicative of flow rate because each rotation relates to a known volume of fluid. Therefore, flow rate sensor 402 effectively provides a flow rate signal that is indicative of an actual rate of fluid flow through the sensor.
  • One method of providing an optical indication is to mark one or more of the lobes of one or both [0069] impellers 408, 410 such that an optical contrast is created. An optical reader then optically detects when the marked lobe has moved, thereby providing an indication of a rotation. Similarly, the reader may be configured to illuminate flow rate sensor 402 (e.g., using an LED) and to thereafter examine the light reflected to detect the output signal (e.g., flow rate signal from flow rate sensor 212 in FIG. 2). In optical detection approaches described herein, the flow sensor itself is preferably passive; the reader supplies the light and processes the returned light to provide a signal to the controller. A controller (e.g., controller 232) can use this information to determine an actual flow rate through flow rate sensor 402. This is so because each rotation of the impellers results in a known volume of fluid passing through the impellers. FIG. 7, which is discussed in greater detail below, illustrates one embodiment of a rotational measurement technique that is particularly suited for use when the flow rate sensor uses a transparent plastic cap.
  • Other methods of detecting rotation are possible. For example, an impeller can include a magnetic component that generates a detectable magnetic field that changes as the impeller rotates (e.g., an electrical variation caused by the rotation of the impeller). Such a changing magnetic field would provide a flow rate signal that could be detected by, for example, a Hall sensor or similar device. [0070]
  • As another alternative, the reader may be made integral with the flow rate sensor itself. For example, a semiconductor device may be used (e.g., a semiconductor that forms or is part of the cap). The rotation rate is detected electronically by the semiconductor device and the output signal is provided directly to the controller, without the use of a reader that is separate from the flow rate sensor. [0071]
  • In one embodiment, [0072] flow rate sensor 402 is constructed using relatively low-cost, precision MEMS and/or micro-molding techniques so that the sensor can be used in connection with a cost-effective, disposable administration set suitable for use in delivering a medical fluid. Thus, the components that do not come directly into contact with the fluid and/or patient (e.g., the pump, controller, and so on) are reusable, while the parts that come into contact with the fluid and/or patient are disposable. In another embodiment, the administration set and infusion pump are both designed to be disposable (e.g., disposed after each use). Two exemplary manufacturing techniques are discussed in greater detail below. It should also be understood that other types of flow sensors and other positive displacement arrangements may be used, and that the illustrated flow rate sensor 402 is provided for exemplary purposes. For example, other configurations of positive displacement flow sensors may use a different number of lobes and/or impellers, or have impellers of varying sizes and shapes—including asymmetrical impellers.
  • FIGS. 5 and 6 illustrate two exemplary methods of manufacturing a flow sensor, such as [0073] flow rate sensor 402, suitable for use in connection with aspects of the present invention. More particularly, FIG. 5 illustrates the pertinent steps of manufacturing a positive displacement flow sensor using a high aspect ratio lithographic process which is sometimes referred to herein as ultra-violet LIGA (UV LIGA) or deep ultra-violet LIGA (DUV LIGA). FIG. 6 illustrates the pertinent steps of manufacturing a positive displacement flow sensor using a deep reactive ion etching sequence (deep RIE).
  • UV LIGA typically results in plastic parts. Deep RIE uses silicon or silicon carbide. Thus, the materials base for each approach differs. Further, both processes may be used to manufacture parts. The UV LIGA approach, however, may be more advantageously practiced if it is used to create replication masters that are used as molds or mold inserts. [0074]
  • Referring first to FIG. 5, generally stated, the UV LIGA approach comprises four [0075] steps 502, 504, 506, and 508. Step 502 involves preparation and exposure. Step 504 involves developing. Step 506 involves electroplating. Step 508 involves removing any remaining photoresist.
  • At [0076] step 502, a mask 510 (e.g., a quartz glass mask with chrome patterns) is placed above a workpiece to be exposed. The workpiece to be exposed comprises a substrate layer 512 (e.g., a silicon wafer). Prior to exposure, a seed layer 514 is attached to the substrate 512 by a deposition process. A photoimageable material, such as an epoxy-based negative photoresist layer 516 (e.g., SU-8) is added on top of substrate 512 (e.g., deposited from a bottle and spin coated). The mask 510 comprises a two-dimensional pattern that is subsequently transferred down to the SU-8 layer. The seed layer 514 is typically nickel, gold, copper, or nickel-ferrite (NiFe). Below seed layer 514 there may also be a “flash” or very thin layer of a refractory metal such as chromium, titanium, or tantalum to act as an adhesion layer. Typically, the flash layer is on the order of 50-500A, and the seed layer is about 400-5000A. Additional information regarding this process may be found at chapter 5 of the “Handbook of Microlithography, Micromachining, and Microfabrication, Volume 2 Micromachining and Microfabrication,” available from SPIE Press 1997. The photoresist layer is selectively exposed to deep UV radiation through the pattern of mask 510.
  • At [0077] step 504, the exposed photoresist layer 516 is developed. The developing solution is a solvent and generally depends on the photoresist being used and whether the photoresist is a positive or negative tone. This development process removes the portions of photoresist layer 516 that were exposed to the UV radiation, leaving structures 530 and 532. At step 506, the remaining structure is electroplated (up from seed layer 514), filling the exposed portions 536 removed during the development process. At step 508, the remaining portions of the photoresist (e.g., structures 530, 532) are developed/etched away, leaving the electroplated structures 540, which may be lifted off of the wafer substrate.
  • It should be appreciated that a number of such [0078] electroplated structures 540, of different sizes and shapes, could be simultaneously formed. For example, one structure could correspond to an impeller (e.g., impeller 408 of FIG. 4A), and another structure could correspond to a housing (e.g., housing 412 of FIGS. 4A and 4B). These structures could thereafter be assembled to form a flow sensor of an appropriate size and shape for use in connection with, for example, the various methods and systems described herein. In other words, structures can be formed for a flow sensor housing having an inlet port and an outlet port, and having pins for accepting first and second impellers. In one embodiment, a clear plastic cover is bonded to the top of the housing, thereby ensuring that substantially all fluid flowing into the flow sensor through the inlet port exits the sensor through the outlet port.
  • It should also be appreciated that, rather than directly using the electroplated [0079] structures 540 for construction a desirable flow sensor, the micro-fabrication processes described herein can be used for creating molds or mold inserts (e.g., negative images of the desired structures). One advantage of such a micro-molding approach is that a large number of molds can be made at once, thereby allowing for large-scale production of flow sensor components, without the need for using the UV LIGA process other than for creating the mold. In one embodiment, components may be made of a plastic or similar material that is suitable for use in a medical environment (e.g., disposable). For example, numerous thermoplastic materials could be used (e.g., polycarbonate or liquid crystal polymer) to mold flow sensors from the master.
  • One advantage of using UV-LIGA is that it does not require the use of an expensive synchrotron radiation source. As mentioned above, there are relatively few synchrotrons in the world. In contrast, UV sources are more readily available and relatively inexpensive, and masters can be created in most moderately equipped semiconductor clean room environments. [0080]
  • Conventional synchrotron LIGA processes require X-Ray masks. These masks are fabricated by starting with standard quartz/chrome masks, with the desired patterns thereon. The patterns are subsequently transferred onto silicon (which is transparent to synchrotron radiation) in the form of gold or beryllium patterns, which absorb radiation. DUV LIGA, in contrast, uses the standard quartz/chrome mask to directly process the SU-8. Therefore, another advantage of using UV LIGA is that the SU-8 material and mask are believed to be less expensive than comparable materials used in conventional synchrotron LIGA. [0081]
  • Referring next to FIG. 6, illustrated therein at [0082] 602, 604, 606, and 608, respectively, are pertinent steps associated with manufacturing a positive displacement flow sensor using a deep RIE micro-fabrication process. In general, deep RIE is a silicon-based process in which deep reactive ion etching is applied to selectively etch away silicon material from the workpiece. The selectivity of the etching process is determined by photolithographic techniques, such as those developed for manufacturing integrated circuits. By its nature, deep RIE provides good verticality, allowing 3-dimension structures to be established from 2-dimension patterns.
  • Deep RIE provides a suitable process for manufacturing flow sensors (either directly or by manufacturing micro-molds) for use in connection with a closed-loop flow control system and method, in accordance with aspects of the invention. One such flow sensor may be created by etching silicon impellers from one substrate, and etching an accepting housing from another substrate (or from another part of a single substrate). The housing preferably includes alignment pins positioned for accepting the impeller gears so that a positive displacement arrangement is formed. The housing also preferably includes a base having a landing. The impeller gears are then placed on their respective rotation pins (either manually or by an automated process). A coverslip (e.g., a clear, heat resistant cover material such as Pyrex®) is thereafter anodically bonded to the landing on the base. All or part of the impellers and/or base surface may be oxidized to produce a desired optical contrast between the respective surfaces. This optical contrast can be used for sensing rotation of the impellers. [0083]
  • FIG. 6 illustrates pertinent steps of producing an impeller and a housing for a flow sensor. Beginning at [0084] 602, a workpiece is prepared comprising a silicon substrate 612 bonded to a base layer 614. The base layer 614 may comprise any number of materials. In one preferred embodiment, base layer 614 comprises another silicon wafer. This can also be done with many different types of adhesive layers, and photoresist may be used as an adhesive layer. Other substrate materials may be used such as, for example, silicon carbide. A photoresist material 616 is applied on the silicon substrate and then patterned using exposure and development steps. Thus, the photoresist is developed to form a 2-dimensional mask pattern so that etching selectively occurs only where desirable to create the part being produced. This pattern is thereafter transferred down into the base layer (e.g., silicon) using reactive ion etching. Many commonly available photoresist materials are suitable. It should be understood that the 2-dimensional mask pattern could be transferred to an alternate layer, such as a silicon nitride or silicon oxide layer.
  • Further, a deposited metal could serve as the etch mask. Such a metallic etch mask would be useful in fabricating relatively tall structures by reactive ion etching techniques. In the etching process, the base layer (e.g., silicon) may be etched at a higher rate than the photoresist layer is being etched (e.g., perhaps 100 times greater). Thus, a photoresist mask may be rendered effective if the etching process is carried out extensively to fabricate tall structures (e.g., several hundred microns deep). In fabricating such tall structures, a metallic etch mask (etched even more selectively than a photoresist) would be useful. [0085]
  • Referring still to FIG. 6, the [0086] photoresist 616 has a 2-dimension shape corresponding to the 3-dimension part being produced. For example, if an impeller is being produced, the photoresist has a 2-dimension shape like that of the desired impeller. The workpiece is selectively exposed and developed so that the exposed silicon is etched away, leaving the base layer, a silicon structure of the desired height and shape, and the photoresist (see 604). Thereafter, the photoresist is stripped away, leaving the base layer and the silicon structure (see 606). Finally, the structure is released from the base layer (see 608).
  • In one embodiment of a flow sensor (e.g., a positive displacement flow sensor) manufactured using deep RIE, the silicon parts are coated with a relatively harder material (e.g., silicon nitride, carbon, or diamond) before the sensor is assembled. Silicon is a hard, but brittle material. As such, a coating improves the strength and integrity of the parts. Also, it should be understood that, rather than manufacturing parts directly, deep RIE can be used to fabricate molds for micro-molding flow sensors in a relatively low-cost, high-volume manner. [0087]
  • In one embodiment, a micro-molded or micro-fabricated flow sensor (e.g., a positive displacement flow sensor) is sized and shaped for being placed in-line with an administration tube (e.g., tube [0088] 204) as part of a disposable administration set. In another embodiment, such a flow sensor is integrated into an infusion set in which the fluid supply, the pump, the administration tube, the flow sensor, the controller and the reader are all part of a disposable unit.
  • Finally, although UV LIGA and/or deep RIE are believed to be two preferred methods for manufacturing flow sensors (or molds therefor), other micro-fabrication techniques may be substituted. These techniques include, for example, synchrotron LIGA and techniques that are not yet available for exploitation. [0089]
  • FIG. 7 is a top view of a [0090] cap piece 700, suitable for use in connection with a positive displacement flow rate sensor, in accordance with aspects of the present invention. As explained above, one method of determining flow rate using a positive displacement flow sensor (e.g., sensor 402 of FIGS. 4A and 4B) involves optically measuring the rotation of the impellers lobes. For example, a small optical spot is used to mark one of the lobes. A reader detects when the marked lobe passes a given point and can thereby detect the rotation rate of the impeller. Because the flow rate sensor is a positive displacement-type sensor, knowledge of the rotation rate corresponds to the actual flow rate. A similar technique involves a detector focused down, into the sensor, that looks for a reflection due to an optical contrast between the base and impeller. If the base is dark and the impeller is relatively light in contrast to the base, most of the reflected light will occur when a lobe passes. Such an approach generally allows a faster detection rate than monitoring a marked lob.
  • FIG. 7 illustrates an alternative to using an optical spot. As illustrated, the [0091] cap piece 700 has imposed thereupon a pattern 702 that replicates one position of the two impellers relative to each other. In one embodiment, pattern 702 is applied to cap piece 700 with additive processes or subtractive processes, creating a roughened surface. The pattern 702 is selected to provide an optical contrast between pattern 702 and the impellers 704. For example, if the impellers are a shade of white, the imposed pattern 702 is a dark shade. A relatively broad light source is applied from above to illuminate the flow sensor. Light is reflected back from the relatively light impeller lobes when the impellers are exposed from behind pattern 702. Thus, as the impellers rotate, the amount of light reflected back (e.g., to an optical detector) varies as a function of the amount of the impeller 704 that is exposed from under pattern 702. Thus, reflection intensity will rise and fall to denote each partial rotation associated with a lobe. For example, the reflected light intensity will increase/decrease at a known number of cycles per revolution, depending upon the number of lobes, thereby providing an indication of the rotation rate of the sensor. Such an approach allows a less precise optical system to be used because the entire filed may be illuminated.
  • It is to be understood that the steps described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated. It is also to be understood that additional or alternative steps may be employed. It should be further appreciated that the novel principles and processes disclosed herein are not limited to the particular embodiments illustrated and described. For instance, flow sensors having a “dual layer” nature can be fabricated (e.g., impellers having pins on the bottom). As a more particular example, impellers having pins fabricated on the bottom can be fabricated using DUV LIGA by adding another layer (i.e., another SU-layer after step [0092] 506), and thereafter, exposing, developing, and electroplating. It is also possible to reverse the order-fabricate pins first and impellers second. Similarly, silicon etching can be used to etch the impellers (or pins). Thereafter, turn the wafer is turned over and attached to a base to etch pins (or impellers).
  • Further, traditional machining fabrication techniques may be employed in connection with aspects of the present invention. In particular, machining can be used in connection with DUV LIGA processing to fabricate features of a mold that are not dimensionally critical. Such features may include, in some embodiments, input and output ports of a positive displacement flow sensor. Similar, in fabricating flow sensors using silicon, a silicon package (e.g., the silicon components and cover slip) can be formed to fit inside a plastic housing that is fabricated by traditional plastic fabrication techniques. Such a plastic housing can include, for example, input and output ports. Other variations are possible. [0093]
  • In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. [0094]
  • When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. [0095]
  • As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. [0096]

Claims (78)

What is claimed is:
1. A system for delivering a fluid at a desired flow rate from a reservoir to a delivery point associated with a patient, said system comprising:
a delivery channel between the reservoir and the delivery point through which the fluid is delivered to the patient;
a pump associated with the delivery channel for operatively delivering the fluid to the delivery point at an adjustable output rate;
a flow sensor located along the delivery channel for sensing a flow of the fluid in the delivery channel and for generating a flow rate signal indicative of a rate of flow of the fluid in the delivery channel, said flow sensor comprising a positive displacement flow sensor; and
a controller for controlling the pump, said controller causing adjustments to the output rate of the pump as a function of the flow rate signal whereby the desired flow rate is substantially achieved.
2. A system as set forth in claim 1 wherein the flow sensor comprises a passive device having no electrical connections thereto.
3. A system as set forth in claim 1 wherein the delivery channel comprises an administration tube and the flow sensor is sized and shaped for being positioned in fluid communication with the fluid within the delivery channel.
4. A system as set forth in claim 3 wherein the flow sensor comprises a MEMS device.
5. A system as set forth in claim 3 wherein the flow sensor comprises an assembly of micro-molded components.
6. A system as set forth in claim 1 wherein the flow sensor is capable of detecting flow rates from about 0.1 ml/hr to about 2000 ml/hr.
7. A system as set forth in claim 1 further comprising a reader associated with the flow sensor for receiving the flow rate signal and providing a flow control signal indicative of the flow rate signal, said controller receiving the flow control signal and adjusting the output rate of the pump in response thereto.
8. A system as set forth in claim 7 wherein the flow sensor comprises a rotatable impeller for rotating in response to the flow of the fluid in the administration tube and the flow rate signal comprises an optical indication generated by a rotation of the rotatable impeller, and wherein the reader comprises an optical reader responsive to the optical indication for providing the flow control signal.
9. A system as set forth in claim 8 wherein:
the optical reader illuminates the flow sensor causing a reflection from the rotatable impeller; and
the optical indication generated by the rotation of the rotatable impeller comprises a variation in an intensity of the reflection from the rotation of the rotatable impeller.
10. A system as set forth in claim 7 wherein:
the flow sensor includes a rotatable impeller for rotating in response to the flow of the fluid in the administration tube; and
the reader comprises a Hall sensor that senses an electrical signal caused by a rotation of the rotatable impeller and provides the flow control signal in response thereto.
11. A system as set forth in claim 1 further comprising:
a reader associated with the flow sensor for receiving the flow rate signal; and
a wireless communication channel between the reader and the controller, said reader providing a flow control signal indicative of the flow rate signal to the wireless communication channel and said controller receiving the flow control signal via the wireless communication channel and causing adjustments to the output rate of the pump in response thereto.
12. A system as set forth in claim 11 wherein the wireless communication channel comprises a spread spectrum communication channel operating in an unlicensed frequency band.
13. A system as set forth in claim 1 wherein the delivery channel comprises an administration tube and the pump comprises an infusion pump located along the administration tube.
14. A system as set forth in claim 13 wherein the infusion pump is a peristaltic pump, a piezoelectric pump or a valve pump.
15. A system as set forth in claim 13 wherein the infusion pump comprises an ambulatory infusion pump.
16. A system as set forth in claim 13 wherein the infusion pump comprises a volumetric infusion pump.
17. A system as set forth in claim 1 wherein the delivery channel comprises an administration tube and the pump comprises an infusion pump connected to the administration tube, and wherein the reservoir comprises a syringe barrel having an input opening and an output orifice operatively connected to the administration tube, and wherein the infusion pump comprises a syringe plunger slidably inserted into the syringe barrel through the input opening and a plunger driver responsive to the controller and operatively connected to the syringe plunger for causing a positive displacement of said syringe plunger, whereby the positive displacement of the plunger operatively delivers the fluid to the delivery point and the output rate of the infusion pump is adjusted by adjusting the positive displacement of the plunger caused by the plunger driver.
18. A system as set forth in claim 1 wherein the desired flow rate comprises a pulsatile flow profile and the controller adjusts the output rate of the pump such that the output flow rate has a generally pulsatile characteristic corresponding to the desired flow rate.
19. A system as set forth in claim 1 wherein the desired flow rate comprises a time-varying flow rate and the controller adjusts the output rate of the pump such that the output flow rate has a time-varying characteristic corresponding to the desired flow rate.
20. A system as set forth in claim 1 wherein the controller provides a flow rate status signal and further comprising a status monitoring device providing an indication of an operating status of the desired flow rate in response to the flow rate status signal.
21. A system as set forth in claim 20 wherein the flow rate status signal comprises a signal indicative of a blockage in the delivery channel and wherein the indication of the operating status of desired flow rate comprises an indication identifying that the delivery channel has a blockage.
22. A system as set forth in claim 20 further comprising a wireless communication channel for transmitting the flow rate status signal from the controller to the status monitoring device.
23. A system as set forth in claim 22 wherein the wireless communication channel comprises a spread spectrum communication channel operating in an unlicensed frequency band.
24. A closed-loop fluid delivery system for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube, said closed-loop fluid delivery system comprising:
fluid delivery means located along the administration tube for operatively supplying the fluid to the delivery point at a controllable output rate;
positive displacement flow sensing means located between the fluid delivery means and the delivery point for sensing an actual flow rate of the fluid in the delivery channel and for generating a flow rate signal indicative of the actual flow rate of the fluid in the delivery channel; and
control means associated with the fluid delivery means receiving and responsive to the flow rate signal for adjusting the output rate of the fluid delivery means such that the desired delivery rate at which the fluid is supplied to the delivery point associated with the patient is substantially achieved.
25. A closed-loop fluid delivery system as set forth in claim 24 wherein the positive displacement flow sensing means is sized and shaped for being positioned in fluid communication with the fluid within the administration tube.
26. A closed-loop fluid delivery system as set forth in claim 24 further comprising detector means associated with the positive displacement flow sensing means for detecting the flow rate signal and for providing a flow control signal indicative of the flow rate signal and wherein the control means receives the flow control signal and adjusts the output rate of the fluid delivery means in response thereto.
27. A closed-loop fluid delivery system as set forth in claim 26 further comprising a wireless communication path between the detector means and the control means wherein the detector means provides the flow control signal to the control means via the wireless communication channel.
28. A closed-loop fluid delivery system as set forth in claim 24 wherein the desired flow rate comprises a pulsatile flow profile and the control means adjusts the output rate of the fluid delivery means such that the output rate has a generally pulsatile characteristic.
29. A closed-loop fluid delivery system as set forth in claim 24 wherein the control means provides a status signal indicative of the actual flow rate and said system further comprising monitoring means receiving the status signal for indicating an operating status of the fluid delivery system.
30. A closed-loop fluid delivery system as set forth in claim 29 wherein the status signal comprises a signal that is indicative of a blockage in the administration tube and wherein the operating status indicated by the monitoring means comprises an indication identifying that the administration tube is blocked.
31. A system for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube, said system comprising:
a delivery mechanism operatively connected between the reservoir and the delivery point, said delivery mechanism being constructed and arranged for selectively delivering the fluid to the delivery point via the administration tube at a controllable output flow rate; and
a closed-loop control system controlling the output flow rate of the delivery mechanism, said closed-loop control system comprising:
a positive displacement flow sensor connected in-line with the administration tube for determining an actual flow rate of the fluid in the administration tube and for providing an flow rate indication reflecting the actual flow rate;
a reader associated with the positive displacement flow sensor for receiving the flow rate indication and for providing a flow control signal reflecting the flow rate indication; and
a controller associated with the delivery mechanism receiving and responsive to the flow control signal for controlling the output flow rate of the delivery mechanism as a function of the flow control signal such that the output flow rate is substantially equal to the desired delivery rate.
32. A system as set forth in claim 31 wherein the positive displacement flow sensor is sized and shaped for being positioned within the administration tube in fluid communication with the fluid.
33. A system as set forth in claim 31 wherein the delivery mechanism comprises an infusion pump.
34. A system as set forth in claim 33 wherein the infusion pump comprises a syringe pump, a peristaltic pump, a piezoelectric pump, or a valve pump.
35. A system as set forth in claim 33 wherein the infusion pump comprises an ambulatory infusion pump.
36. A system as set forth in claim 33 wherein the infusion pump comprises a volumetric infusion pump.
37. A system as set forth in claim 31 further comprising a wireless communication path between the reader and the controller, said reader providing the flow control signal to the controller via the wireless communication path.
38. A system as set forth in claim 31 wherein the desired delivery rate comprises a pulsatile delivery profile and wherein the controller controls the delivery mechanism such that output flow rate has a substantially pulsatile characteristic.
39. A system as set forth in claim 31 further comprising a status monitor and wherein the closed-loop control system provides a status signal indicating when the actual flow rate is below a flow rate threshold, said status monitor receiving the status signal and providing an indication that the actual flow rate is below the flow rate threshold.
40. A system as set forth in claim 39 wherein the indication that the actual flow rate is below the flow rate threshold comprises an audible alarm.
41. A system as set forth in claim 39 wherein the indication that the actual flow rate is below the flow rate threshold comprises a visual alarm.
42. A system as set forth in claim 39 wherein the indication that the actual flow rate is below the flow rate threshold comprises a vibrating alarm.
43. A method of delivering a medical fluid to a delivery point associated with a patient at a desired delivery flow rate comprising:
operatively connecting a reservoir to a delivery mechanism, said reservoir containing the medical fluid to be delivered to the delivery point;
operatively connecting the delivery mechanism to an administration tube, said administration tube being in fluid communication with the delivery point, said delivery mechanism receiving the medical fluid from the reservoir and supplying the medical fluid to the delivery point via the administration tube at an output flow rate;
sensing the output flow rate of the medical fluid in the administration tube using a positive displacement flow sensor;
comparing the sensed output flow rate of the medical fluid with the desired delivery flow rate; and
controlling the delivery mechanism such that the output flow rate substantially corresponds to the desired delivery flow rate.
44. A method as set forth in claim 43 wherein sensing the output flow rate of the medical fluid in the administration tube comprises connecting a flow sensor operatively to the administration tube and wherein sensing the output flow rate of the medical fluid in the administration tube comprises sensing a rate of flow through the flow sensor whereby the generated flow rate signal is a function of the rate of flow through the flow sensor.
45. A method as set forth in claim 44 wherein the positive displacement flow sensor is sized and shaped for being positioned in fluid communication with the medical fluid within the administration tube.
46. A method as set forth in claim 45 wherein the positive displacement flow sensor includes a rotatable member and wherein each rotation of the rotatable member corresponds to a fixed volume of the medical fluid passing through the positive displacement flow sensor, and wherein sensing the rate of flow through the positive displacement flow sensor comprises:
sensing a rotation of the rotatable member; and
calculating the rate of flow as a function of a number of rotations of the rotatable member over a sample period.
47. A method as set forth in claim 46 further comprising providing an optical variation based on the rotation of the rotatable member and wherein sensing the rotation of the rotatable member comprises sensing the optical variation provided by the rotation of the rotatable member.
48. A method as set forth in claim 46 wherein the rotation of the rotatable member causes an electrical variation and wherein sensing the rotation of the rotatable member comprises sensing the electrical variation caused by the rotation of the rotatable member.
49. A method as set forth in claim 44 wherein the delivery mechanism comprises an infusion pump and supplying the medical fluid to the administration tube at the output flow rate comprises pumping the medical fluid through the administration tube such that desired delivery flow rate is substantially achieved.
50. A method as set forth in claim 49 wherein the administration tube and flow sensor comprise an administration set constructed and arranged for disposable use.
51. A method as set forth in claim 49 wherein the desired flow rate comprises a pulsatile flow profile and wherein controlling the delivery mechanism comprises controlling the infusion pump such that the output flow rate has a generally pulsatile characteristic.
52. A method as set forth in claim 43 further comprising:
determining if the sensed output flow rate is indicative of a blockage in the administration tube; and
providing an alarm signal if it is determined that the sensed output flow rate indicates a blockage in the administration tube.
53. A method as set forth in claim 43 wherein comparing the sensed output flow rate of the medical fluid with the desired delivery flow rate comprises comparing an average of the output flow rate of the medical fluid with the output flow rate.
54. A method as set forth in claim 43 wherein comparing the sensed output flow rate of the medical fluid with the desired delivery flow rate comprises comparing the sensed output flow rate of the medical fluid with an acceptability range corresponding to the output flow rate.
55. A closed-loop flow control system for controlling a medical fluid delivery system, said medical fluid delivery system delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate via an administration tube, said medical fluid delivery system including a delivery mechanism operatively connected between the reservoir and the delivery point, said delivery mechanism being constructed and arranged for delivering the fluid to the delivery point via the administration tube at a controllable output flow rate, said closed-loop flow control system comprising:
a positive displacement flow sensor connected in-line with the administration tube for determining an actual flow rate of the fluid in the administration tube and for providing an flow rate indication reflecting the actual flow rate;
a reader associated with the positive displacement flow sensor for receiving the flow rate indication and for providing a flow control signal reflecting the flow rate indication; and
a controller associated with the delivery mechanism receiving and responsive to the flow control signal for controlling the output flow rate of the delivery mechanism as a function of the flow control signal such that the output flow rate is substantially equal to the desired delivery rate.
56. A closed-loop flow control system as set forth in claim 55 wherein the positive displacement flow sensor is sized and shaped for being positioned within the administration tube in fluid communication with the medical fluid.
57. A closed-loop flow control system as set forth in claim 55 further comprising a wireless communication channel between the reader and the controller, said reader providing the flow control signal to the controller via the wireless communication channel.
58. A closed-loop flow control system as set forth in claim 55 wherein the desired delivery rate comprises a pulsatile delivery profile and wherein the controller controls the delivery mechanism such that output flow rate includes a substantially pulsatile characteristic.
59. A method of detecting a blockage in a medical fluid delivery system arranged for delivering a medical fluid to a delivery point associated with a patient at a desired flow rate, the method comprising:
operatively connecting a reservoir to a delivery mechanism, said reservoir containing the medical fluid to be delivered to the delivery point;
operatively connecting the delivery mechanism to an administration tube, said administration tube being in fluid communication with the delivery point, said delivery mechanism receiving the medical fluid from the reservoir and supplying the medical fluid to the delivery point via the administration tube at an output flow rate;
sensing the output flow rate of the medical fluid in the administration tube;
determining if the sensed output flow rate is indicative of a blockage in the administration tube; and
providing an alarm signal if it is determined that the sensed output flow rate indicates that the administration tube is blocked.
60. A method as set forth in claim 59 wherein determining if the sensed output flow rate is indicative of a blockage in the administration tube comprises comparing the sensed output flow rate to a blockage threshold such that the alarm signal is provided if the output flow rate is less than the blockage threshold.
61. A method as set forth in claim 60 wherein determining if the sensed output flow is indicative of a blockage in the administration tube comprises averaging the sensed output flow rate of the medical fluid in the administration tube over a time period and comparing said averaged sensed output flow rate to a blockage reference such that the alarm signal is provided if the averaged sensed flow rate is less than the blockage reference.
62. A method as set forth in claim 59 further comprising receiving the alarm signal at a status monitoring device associated with the medical fluid delivery system and providing an indication of the alarm signal at the status monitoring device.
63. A method as set fort hin claim 62 wherein the indication of the alarm signal comprises an audible alarm.
64. A method as set forth in claim 62 wherein the indication of the alarm signal comprises a visual alarm.
65. A method as set forth in claim 64 wherein the indication of the alarm signal comprises a vibrating alarm.
66. An administration set for use in connection with a fluid delivery system, said fluid delivery system being arranged for delivering a fluid from a reservoir to a delivery point associated with a patient at a desired delivery rate, and wherein said fluid delivery system includes a pump having an output rate for delivering fluid from the reservoir to the delivery point and a controller for adjusting the output rate of the pump such that the desired delivery rate is substantially achieved, the administration set comprising:
an administration tube for providing fluid communication between the reservoir and the delivery point; and
a positive displacement flow sensor located along the administration tube being sized and shaped for being positioned in fluid communication with the fluid within the administration tube, said positive displacement flow sensor for sensing a rate of flow of the fluid in the administration tube and for generating a flow rate signal indicative of the sensed rate of flow of the fluid in the administration tube whereby the controller adjusts the output rate of the pump as a function of the flow rate signal.
67. An administration set as set forth in claim 66 wherein the positive displacement flow sensor is sized and shaped for being positioned within the administration tube such that substantially all of the fluid flowing through the administration tube to the delivery point flows through the flow sensor.
68. A positive displacement flow sensor for use in connection with a medical fluid infusion system including an administration set having an administration tube, the positive displacement flow sensor comprising:
a housing having an inlet port and an outlet port, said ports being operatively connected to the administration tube;
a first rotor positioned within the housing between the inlet port and the outlet port;
a second rotor positioned within the housing between the inlet port and the outlet port, said second rotor being positioned adjacent to the first rotor, said first and second rotors being constructed and arranged to rotate in response to a flow of medical fluid in the administration tube for detecting flow of the medical fluid in the administration tube; and
a cover enclosing the housing such that when the medical fluid flows into the inlet port it causes the first rotor to rotate and thereafter said medical fluid exits through the outlet port.
69. A positive displacement flow sensor as set forth in claim 68 wherein the first and second rotors each have a plurality of lobes, said lobes of the first rotor engaging said lobes of the second rotor in a gearing relationship.
70. A positive displacement flow sensor as set forth in claim 68 wherein the housing and the first and second rotors are fabricated using micro-fabrication techniques.
71. A positive displacement flow sensor as set forth in claim 68 wherein the housing and the first and second rotors are fabricated from one or more molds created via a UV-LIGA process.
72. A positive displacement flow sensor as set forth in claim 68 wherein the housing and the first and second rotors are fabricated using a deep reactive ion etching process.
73. A positive displacement flow sensor as set forth in claim 68 wherein the cover comprises a generally transparent cover allowing light to pass through a portion of the cover.
74. A positive displacement flow sensor as set forth in claim 73 wherein the first rotor comprises a plurality of lobes, at least one of said lobes being marked with a marker indication that is optically detectable through the cover.
75. A positive displacement flow sensor as set forth in claim 73 wherein the cover has a substantially opaque pattern imposed thereon that substantially prevents light from passing through said pattern.
76. A positive displacement flow sensor as set forth in claim 75 wherein the pattern imposed on the cover corresponds to a shape and size of the first rotor.
77. A positive displacement flow sensor as set forth in claim 68 further comprising a reader positioned adjacent the first rotor, said reader being constructed and arranged for detecting a rotation of the first rotor and for providing a signal that is indicative of a rate of the flow of the medical fluid in the administration tube as a function of the detected rotation of the first rotor.
78. A positive displacement flow sensor as set forth in claim 77 wherein the reader is positioned substantially within the cover.
US10/177,544 2002-06-21 2002-06-21 Method and apparatus for closed-loop flow control system Abandoned US20030236489A1 (en)

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US10/177,544 US20030236489A1 (en) 2002-06-21 2002-06-21 Method and apparatus for closed-loop flow control system
TW092115004A TWI238069B (en) 2002-06-21 2003-06-03 Method and apparatus for closed-loop flow control system
MXPA04012657A MXPA04012657A (en) 2002-06-21 2003-06-05 Fluid delivery system with closed-loop flow control and method.
PCT/US2003/017740 WO2004000394A1 (en) 2002-06-21 2003-06-05 Fluid delivery system with closed-loop flow control and method
KR10-2004-7020727A KR20050014869A (en) 2002-06-21 2003-06-05 Fluid delivery system with closed-loop flow control and method
EP03736858A EP1515762A1 (en) 2002-06-21 2003-06-05 Fluid delivery system with closed-loop flow control and method
AU2003237402A AU2003237402A1 (en) 2002-06-21 2003-06-05 Fluid delivery system with closed-loop flow control and method
CNB038141477A CN100548399C (en) 2002-06-21 2003-06-05 Fluid delivery system with closed-loop flow control
AR20030102217A AR040448A1 (en) 2002-06-21 2003-06-20 METHOD AND APPLIANCE FOR FLOW CONTROL SYSTEM BY CLOSED LOOP
US11/333,594 US7879025B2 (en) 2002-06-21 2006-01-17 Fluid delivery system and flow control therefor
US12/053,134 US8231566B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor
US12/053,120 US8672876B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor
US12/053,156 US8226597B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor

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US11/333,594 Expired - Fee Related US7879025B2 (en) 2002-06-21 2006-01-17 Fluid delivery system and flow control therefor
US12/053,156 Expired - Fee Related US8226597B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor
US12/053,134 Expired - Fee Related US8231566B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor
US12/053,120 Expired - Fee Related US8672876B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor

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US12/053,134 Expired - Fee Related US8231566B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor
US12/053,120 Expired - Fee Related US8672876B2 (en) 2002-06-21 2008-03-21 Fluid delivery system and flow control therefor

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Cited By (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006089965A1 (en) * 2005-02-28 2006-08-31 Novo Nordisk A/S Device for providing a change in a drug delivery rate
US20060288803A1 (en) * 2003-11-05 2006-12-28 Agilent Technologies, Inc. Chromatography system with blockage determination
WO2007065145A2 (en) * 2005-12-02 2007-06-07 The Cooper Health System Regional anesthetic method and apparatus
US20080200897A1 (en) * 2007-02-19 2008-08-21 Abbott Diabetes Care, Inc. Modular combination of medication infusion and analyte monitoring
US20090012812A1 (en) * 2007-03-06 2009-01-08 Tracy Rausch System and method for patient care
US7645238B2 (en) 2005-12-02 2010-01-12 The Cooper Health System Regional anesthetic method and apparatus
US20100264931A1 (en) * 2009-04-16 2010-10-21 Roche Diagnostics International Ag Ambulatory infusion device with sensor testing unit
EP2277575A1 (en) * 2008-01-08 2011-01-26 Baxter International Inc. System and method for detecting occlusion using flow sensor output
US20110040251A1 (en) * 2008-01-09 2011-02-17 Michael Blomquist Infusion pump with add-on modules
US7944366B2 (en) * 2005-09-19 2011-05-17 Lifescan, Inc. Malfunction detection with derivative calculation
US7955319B2 (en) 2003-10-02 2011-06-07 Medtronic, Inc. Pressure sensing in implantable medical devices
US8317770B2 (en) 2006-04-06 2012-11-27 Medtronic, Inc. Systems and methods of identifying catheter malfunctions using pressure sensing
US8323244B2 (en) 2007-03-30 2012-12-04 Medtronic, Inc. Catheter malfunction determinations using physiologic pressure
US20130204202A1 (en) * 2012-02-08 2013-08-08 Stmicroelectronics, Inc. Wireless strain gauge/flow sensor
US8777897B2 (en) 2009-07-06 2014-07-15 Carefusion 303, Inc. Fluid delivery systems and methods having wireless communication
US20150023808A1 (en) * 2013-07-22 2015-01-22 Baxter Healthcare S.A. Infusion pump including reverse loading protection
US9033920B2 (en) 2003-10-02 2015-05-19 Medtronic, Inc. Determining catheter status
US20150148739A1 (en) * 2013-11-27 2015-05-28 April Marie Radicella Simplified Microplegia Delivery System
US9044537B2 (en) 2007-03-30 2015-06-02 Medtronic, Inc. Devices and methods for detecting catheter complications
US9138537B2 (en) 2003-10-02 2015-09-22 Medtronic, Inc. Determining catheter status
US9375531B2 (en) * 2011-10-27 2016-06-28 Zyno Medical, Llc Syringe pump with improved flow monitoring
US9669160B2 (en) 2014-07-30 2017-06-06 Tandem Diabetes Care, Inc. Temporary suspension for closed-loop medicament therapy
US9833177B2 (en) 2007-05-30 2017-12-05 Tandem Diabetes Care, Inc. Insulin pump based expert system
US20180078700A1 (en) * 2016-09-16 2018-03-22 Dentsply Ih Ab Motorized irrigation system with improved flow control
US10016559B2 (en) 2009-12-04 2018-07-10 Smiths Medical Asd, Inc. Advanced step therapy delivery for an ambulatory infusion pump and system
US10016561B2 (en) 2013-03-15 2018-07-10 Tandem Diabetes Care, Inc. Clinical variable determination
US10052049B2 (en) 2008-01-07 2018-08-21 Tandem Diabetes Care, Inc. Infusion pump with blood glucose alert delay
US10226207B2 (en) 2004-12-29 2019-03-12 Abbott Diabetes Care Inc. Sensor inserter having introducer
US10357607B2 (en) 2007-05-24 2019-07-23 Tandem Diabetes Care, Inc. Correction factor testing using frequent blood glucose input
US10357606B2 (en) 2013-03-13 2019-07-23 Tandem Diabetes Care, Inc. System and method for integration of insulin pumps and continuous glucose monitoring
US10384004B2 (en) * 2013-01-21 2019-08-20 Baxter International Inc. Infusion pump and method to enhance long term medication delivery accuracy
US10569016B2 (en) 2015-12-29 2020-02-25 Tandem Diabetes Care, Inc. System and method for switching between closed loop and open loop control of an ambulatory infusion pump
CN112524493A (en) * 2020-12-29 2021-03-19 广东石油化工学院 Device for transmitting control signal by using pipeline fluid
CN112915311A (en) * 2021-02-09 2021-06-08 苏州原位芯片科技有限责任公司 Negative feedback system control method, micropump and medical pump system
US11076904B2 (en) * 2018-12-20 2021-08-03 Avent, Inc. Flow rate control for a cooled medical probe assembly
US11291763B2 (en) 2007-03-13 2022-04-05 Tandem Diabetes Care, Inc. Basal rate testing using frequent blood glucose input
US11672695B2 (en) 2018-03-22 2023-06-13 Artivion, Inc. Central nervous system localized hypothermia apparatus and methods
US11676694B2 (en) 2012-06-07 2023-06-13 Tandem Diabetes Care, Inc. Device and method for training users of ambulatory medical devices
US11865541B2 (en) 2020-06-12 2024-01-09 Biofluidica, Inc. Dual-depth thermoplastic microfluidic device and related systems and methods
US11872368B2 (en) 2018-04-10 2024-01-16 Tandem Diabetes Care, Inc. System and method for inductively charging a medical device

Families Citing this family (142)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7287398B2 (en) * 2001-09-25 2007-10-30 Alsius Corporation Heating/cooling system for indwelling heat exchange catheter
US8034026B2 (en) 2001-05-18 2011-10-11 Deka Products Limited Partnership Infusion pump assembly
WO2002094352A2 (en) 2001-05-18 2002-11-28 Deka Products Limited Partnership Infusion set for a fluid pump
CN101394878A (en) * 2006-02-09 2009-03-25 德卡产品有限公司 Peripheral systems
US20080119782A1 (en) * 2006-10-25 2008-05-22 Steinman Christopher P Method for delivering solutions to a patient
US8430837B2 (en) 2007-02-05 2013-04-30 Boston Scientific Scimed, Inc. Thrombectomy apparatus and method
US8147447B2 (en) * 2007-09-17 2012-04-03 Satish Sundar High precision infusion pump controller
US9656019B2 (en) 2007-10-02 2017-05-23 Medimop Medical Projects Ltd. Apparatuses for securing components of a drug delivery system during transport and methods of using same
US7967795B1 (en) 2010-01-19 2011-06-28 Lamodel Ltd. Cartridge interface assembly with driving plunger
US9345836B2 (en) 2007-10-02 2016-05-24 Medimop Medical Projects Ltd. Disengagement resistant telescoping assembly and unidirectional method of assembly for such
WO2009044401A2 (en) 2007-10-02 2009-04-09 Yossi Gross External drug pump
US10420880B2 (en) 2007-10-02 2019-09-24 West Pharma. Services IL, Ltd. Key for securing components of a drug delivery system during assembly and/or transport and methods of using same
US8517990B2 (en) 2007-12-18 2013-08-27 Hospira, Inc. User interface improvements for medical devices
EP2276524B1 (en) * 2008-05-07 2011-12-28 Roche Diagnostics GmbH Display for an infusion delivery system
US8065924B2 (en) 2008-05-23 2011-11-29 Hospira, Inc. Cassette for differential pressure based medication delivery flow sensor assembly for medication delivery monitoring and method of making the same
US8784367B2 (en) * 2008-07-08 2014-07-22 Koninklijke Philips N.V Sensor and control unit for flow control and a method for controlled delivery of fluid
US7819838B2 (en) * 2008-09-02 2010-10-26 Hospira, Inc. Cassette for use in a medication delivery flow sensor assembly and method of making the same
US9393369B2 (en) 2008-09-15 2016-07-19 Medimop Medical Projects Ltd. Stabilized pen injector
US8016789B2 (en) 2008-10-10 2011-09-13 Deka Products Limited Partnership Pump assembly with a removable cover assembly
US8262616B2 (en) 2008-10-10 2012-09-11 Deka Products Limited Partnership Infusion pump assembly
US8708376B2 (en) 2008-10-10 2014-04-29 Deka Products Limited Partnership Medium connector
US8066672B2 (en) * 2008-10-10 2011-11-29 Deka Products Limited Partnership Infusion pump assembly with a backup power supply
US8223028B2 (en) 2008-10-10 2012-07-17 Deka Products Limited Partnership Occlusion detection system and method
US9180245B2 (en) * 2008-10-10 2015-11-10 Deka Products Limited Partnership System and method for administering an infusible fluid
US8267892B2 (en) 2008-10-10 2012-09-18 Deka Products Limited Partnership Multi-language / multi-processor infusion pump assembly
US9510854B2 (en) 2008-10-13 2016-12-06 Boston Scientific Scimed, Inc. Thrombectomy catheter with control box having pressure/vacuum valve for synchronous aspiration and fluid irrigation
US20100114027A1 (en) * 2008-11-05 2010-05-06 Hospira, Inc. Fluid medication delivery systems for delivery monitoring of secondary medications
US8048022B2 (en) * 2009-01-30 2011-11-01 Hospira, Inc. Cassette for differential pressure based medication delivery flow sensor assembly for medication delivery monitoring and method of making the same
US8069719B2 (en) * 2009-02-11 2011-12-06 Ecolab Usa Inc. Gear flow meter with optical sensor
US8157769B2 (en) 2009-09-15 2012-04-17 Medimop Medical Projects Ltd. Cartridge insertion assembly for drug delivery system
US10071196B2 (en) 2012-05-15 2018-09-11 West Pharma. Services IL, Ltd. Method for selectively powering a battery-operated drug-delivery device and device therefor
US10071198B2 (en) 2012-11-02 2018-09-11 West Pharma. Servicees IL, Ltd. Adhesive structure for medical device
CN102058915B (en) * 2009-11-17 2013-04-17 西安交通大学医学院第二附属医院 Medical constant speed transfusion device
JP4956655B2 (en) * 2009-11-25 2012-06-20 株式会社リコー Infusion pump module and infusion system
CA2783367A1 (en) * 2009-12-18 2011-06-23 K&Y Corporation Infusion pump
US20110152697A1 (en) * 2009-12-18 2011-06-23 K&Y Corporation Circulatory Pressure Monitoring Using Infusion Pump Systems
US20110152829A1 (en) * 2009-12-18 2011-06-23 K&Y Corporation Patient Fluid Management System
US8348898B2 (en) 2010-01-19 2013-01-08 Medimop Medical Projects Ltd. Automatic needle for drug pump
WO2011123503A1 (en) 2010-04-01 2011-10-06 B & H Manufacturing Company, Inc. Extrusion application system
EP2569031B1 (en) 2010-05-10 2017-10-11 Medimop Medical Projects Ltd. Low volume accurate injector
US8858185B2 (en) * 2010-06-23 2014-10-14 Hospira, Inc. Fluid flow rate compensation system using an integrated conductivity sensor to monitor tubing changes
WO2012037428A2 (en) 2010-09-16 2012-03-22 The Cleveland Clinic Foundation Lacrimal drainage manometer and method of use
US8932231B2 (en) * 2010-09-16 2015-01-13 The Cleveland Clinic Foundation Lacrimal drainage manometer and method of use
KR101851378B1 (en) 2010-10-01 2018-04-23 제벡스, 아이엔씨. Method for improving accuracy in a peristaltic pump system based on tubing material properties
WO2012044807A2 (en) 2010-10-01 2012-04-05 Zevex, Inc. Anti free-flow occluder and priming actuator pad
US8752436B2 (en) 2010-10-01 2014-06-17 Zevex, Inc. Pressure sensor seal and method of use
USD672455S1 (en) 2010-10-01 2012-12-11 Zevex, Inc. Fluid delivery cassette
US9004886B2 (en) 2010-10-01 2015-04-14 Zevex, Inc. Pressure monitoring system for infusion pumps
USD702834S1 (en) 2011-03-22 2014-04-15 Medimop Medical Projects Ltd. Cartridge for use in injection device
AU2012299169B2 (en) 2011-08-19 2017-08-24 Icu Medical, Inc. Systems and methods for a graphical interface including a graphical representation of medical data
WO2013043424A1 (en) * 2011-09-12 2013-03-28 The Cleveland Clinic Foundation Assembly for indicating fluid flow
KR101297661B1 (en) 2011-10-12 2013-08-21 부산대학교 산학협력단 Syringe pump simulator
CN103120818B (en) * 2011-10-27 2016-12-21 西诺医药有限责任公司 There is the syringe pump of the flow monitoring of improvement
US20130138075A1 (en) 2011-11-30 2013-05-30 Emed Technologies Corp. (Nv) Variable flow control device, system and method
US10022498B2 (en) 2011-12-16 2018-07-17 Icu Medical, Inc. System for monitoring and delivering medication to a patient and method of using the same to minimize the risks associated with automated therapy
WO2013115843A1 (en) 2012-01-31 2013-08-08 Medimop Medical Projects Ltd. Time dependent drug delivery apparatus
US9782543B2 (en) * 2012-02-13 2017-10-10 Sanofi-Aventis Deutschland Gmbh Pen-type drug injection device and electronic add-on monitoring module for monitoring and logging dose setting and administration
GB201202926D0 (en) * 2012-02-21 2012-04-04 Central Manchester University Hospitals Nhs Foundation Trust Inhaler spacer
CN102536755B (en) * 2012-03-01 2015-10-28 苏州大学 A kind of closed-loop piezoelectric film pump and flow control method
US9072827B2 (en) 2012-03-26 2015-07-07 Medimop Medical Projects Ltd. Fail safe point protector for needle safety flap
US10668213B2 (en) 2012-03-26 2020-06-02 West Pharma. Services IL, Ltd. Motion activated mechanisms for a drug delivery device
US9463280B2 (en) 2012-03-26 2016-10-11 Medimop Medical Projects Ltd. Motion activated septum puncturing drug delivery device
WO2013148798A1 (en) 2012-03-30 2013-10-03 Hospira, Inc. Air detection system and method for detecting air in a pump of an infusion system
CN102688535B (en) * 2012-05-25 2014-07-09 中国航天科技集团公司第九研究院第七七一研究所 Medical infusion automatic alarm based on Hall integrated circuit and infusion apparatus with same
CA3089257C (en) 2012-07-31 2023-07-25 Icu Medical, Inc. Patient care system for critical medications
ITMI20121424A1 (en) * 2012-08-09 2014-02-10 Milano Politecnico INSTRUMENT FOR DEPOSITION OF ADIPOSE FABRIC IN LIPOMODELING
US20140081218A1 (en) * 2012-09-06 2014-03-20 Memorial Sloan-Kettering Cancer Center Intravenous device having a movable arrangement
US10842931B2 (en) 2012-12-17 2020-11-24 Board Of Regents Of The University Of Texas System System of intravenous fluid/medication delivery that employs signature flow amplitudes of frequencies to facilitate the detection of intravenous infiltration
US10065003B2 (en) 2012-12-28 2018-09-04 Gambro Lundia Ab Syringe pump engagement detection apparatus and methods
US9421323B2 (en) 2013-01-03 2016-08-23 Medimop Medical Projects Ltd. Door and doorstop for portable one use drug delivery apparatus
US9011164B2 (en) 2013-04-30 2015-04-21 Medimop Medical Projects Ltd. Clip contact for easy installation of printed circuit board PCB
US9889256B2 (en) 2013-05-03 2018-02-13 Medimop Medical Projects Ltd. Sensing a status of an infuser based on sensing motor control and power input
US10046112B2 (en) 2013-05-24 2018-08-14 Icu Medical, Inc. Multi-sensor infusion system for detecting air or an occlusion in the infusion system
AU2014274122A1 (en) 2013-05-29 2016-01-21 Icu Medical, Inc. Infusion system and method of use which prevents over-saturation of an analog-to-digital converter
EP3003441B1 (en) 2013-05-29 2020-12-02 ICU Medical, Inc. Infusion system which utilizes one or more sensors and additional information to make an air determination regarding the infusion system
US10451075B1 (en) 2013-06-10 2019-10-22 Villicus, Inc. Saltwater disposal
US10138882B1 (en) 2013-06-10 2018-11-27 Villicus, Inc. Controlling a pump
CN105579080B (en) * 2013-09-24 2019-09-10 Kpr美国有限责任公司 It feeds external member and enteral feeds pump
US20150133861A1 (en) 2013-11-11 2015-05-14 Kevin P. McLennan Thermal management system and method for medical devices
DE102013113387A1 (en) * 2013-12-03 2015-06-03 Ulrich Gmbh & Co. Kg Injector for injecting a fluid and method for controlling an injector
CN103691018A (en) * 2014-01-09 2014-04-02 上海理工大学 Medical perfusion type irrigator
EP3110474B1 (en) 2014-02-28 2019-12-18 ICU Medical, Inc. Infusion system and method which utilizes dual wavelength optical air-in-line detection
US9248221B2 (en) 2014-04-08 2016-02-02 Incuvate, Llc Aspiration monitoring system and method
US9433427B2 (en) 2014-04-08 2016-09-06 Incuvate, Llc Systems and methods for management of thrombosis
ES2935770T3 (en) 2014-05-06 2023-03-09 Univ North Carolina Chapel Hill Devices, systems and procedures for volumetrically measuring fluid in a syringe
US9883877B2 (en) 2014-05-19 2018-02-06 Walk Vascular, Llc Systems and methods for removal of blood and thrombotic material
CA2947045C (en) 2014-05-29 2022-10-18 Hospira, Inc. Infusion system and pump with configurable closed loop delivery rate catch-up
US10143795B2 (en) 2014-08-18 2018-12-04 Icu Medical, Inc. Intravenous pole integrated power, control, and communication system and method for an infusion pump
US11344668B2 (en) 2014-12-19 2022-05-31 Icu Medical, Inc. Infusion system with concurrent TPN/insulin infusion
US10850024B2 (en) 2015-03-02 2020-12-01 Icu Medical, Inc. Infusion system, device, and method having advanced infusion features
US9795534B2 (en) 2015-03-04 2017-10-24 Medimop Medical Projects Ltd. Compliant coupling assembly for cartridge coupling of a drug delivery device
US10251813B2 (en) 2015-03-04 2019-04-09 West Pharma. Services IL, Ltd. Flexibly mounted cartridge alignment collar for drug delivery device
US10293120B2 (en) 2015-04-10 2019-05-21 West Pharma. Services IL, Ltd. Redundant injection device status indication
US9744297B2 (en) 2015-04-10 2017-08-29 Medimop Medical Projects Ltd. Needle cannula position as an input to operational control of an injection device
ES2809505T3 (en) 2015-05-26 2021-03-04 Icu Medical Inc Disposable infusion fluid delivery device for programmable delivery of high volume drugs
US10149943B2 (en) 2015-05-29 2018-12-11 West Pharma. Services IL, Ltd. Linear rotation stabilizer for a telescoping syringe stopper driverdriving assembly
US10702292B2 (en) 2015-08-28 2020-07-07 Incuvate, Llc Aspiration monitoring system and method
CN113521439B (en) * 2015-08-28 2023-04-25 拜耳医药保健有限公司 System and method for syringe fluid filling verification and image recognition of power injector system features
US10561440B2 (en) 2015-09-03 2020-02-18 Vesatek, Llc Systems and methods for manipulating medical devices
JPWO2017047224A1 (en) * 2015-09-14 2018-07-05 テルモ株式会社 Chemical solution administration device
US10576207B2 (en) 2015-10-09 2020-03-03 West Pharma. Services IL, Ltd. Angled syringe patch injector
US9987432B2 (en) 2015-09-22 2018-06-05 West Pharma. Services IL, Ltd. Rotation resistant friction adapter for plunger driver of drug delivery device
US20170100142A1 (en) 2015-10-09 2017-04-13 Incuvate, Llc Systems and methods for management of thrombosis
CN108472438B (en) 2015-10-09 2022-01-28 西医药服务以色列分公司 Tortuous fluid path attachment to pre-filled fluid reservoirs
US10226263B2 (en) 2015-12-23 2019-03-12 Incuvate, Llc Aspiration monitoring system and method
EP3711793B1 (en) 2016-01-21 2021-12-01 West Pharma Services IL, Ltd. A method of connecting a cartridge to an automatic injector
CN109310816B (en) 2016-01-21 2020-04-21 西医药服务以色列有限公司 Needle insertion and retraction mechanism
CN113041432B (en) 2016-01-21 2023-04-07 西医药服务以色列有限公司 Medicament delivery device comprising a visual indicator
WO2017161076A1 (en) 2016-03-16 2017-09-21 Medimop Medical Projects Ltd. Staged telescopic screw assembly having different visual indicators
CA3018731A1 (en) * 2016-03-21 2017-09-28 Advanced Grow Labs Technologies, Llc Vaporizing device system and method
US10492805B2 (en) 2016-04-06 2019-12-03 Walk Vascular, Llc Systems and methods for thrombolysis and delivery of an agent
US11246985B2 (en) 2016-05-13 2022-02-15 Icu Medical, Inc. Infusion pump system and method with common line auto flush
WO2017210448A1 (en) 2016-06-02 2017-12-07 Medimop Medical Projects Ltd. Three position needle retraction
CA3027176A1 (en) 2016-06-10 2017-12-14 Icu Medical, Inc. Acoustic flow sensor for continuous medication flow measurements and feedback control of infusion
WO2018005592A1 (en) * 2016-06-28 2018-01-04 University Of Iowa Research Foundation Medical devices including rotary valve
WO2018026387A1 (en) 2016-08-01 2018-02-08 Medimop Medical Projects Ltd. Anti-rotation cartridge pin
US11730892B2 (en) 2016-08-01 2023-08-22 West Pharma. Services IL, Ltd. Partial door closure prevention spring
WO2018061562A1 (en) 2016-09-27 2018-04-05 テルモ株式会社 Liquid medicine administration device
WO2018132430A1 (en) 2017-01-10 2018-07-19 A.T. Still Universiy Fluid infusion system
WO2018148427A1 (en) 2017-02-10 2018-08-16 Baxter International Inc. Volume-based flow rate compensation technique for infusion therapy
US11819666B2 (en) 2017-05-30 2023-11-21 West Pharma. Services IL, Ltd. Modular drive train for wearable injector
CN109925573A (en) * 2017-12-17 2019-06-25 喻雯婷 Auxiliary device and control method for infusion
CN111683703B (en) 2017-12-22 2022-11-18 西氏医药包装(以色列)有限公司 Syringe adapted for cartridges of different sizes
US10089055B1 (en) 2017-12-27 2018-10-02 Icu Medical, Inc. Synchronized display of screen content on networked devices
US11678905B2 (en) 2018-07-19 2023-06-20 Walk Vascular, Llc Systems and methods for removal of blood and thrombotic material
USD939079S1 (en) 2019-08-22 2021-12-21 Icu Medical, Inc. Infusion pump
US11278671B2 (en) 2019-12-04 2022-03-22 Icu Medical, Inc. Infusion pump with safety sequence keypad
CN111282137A (en) * 2020-03-02 2020-06-16 孙富广 Special urethral catheterization device for urinary surgery in hospital and control method
CA3189781A1 (en) 2020-07-21 2022-01-27 Icu Medical, Inc. Fluid transfer devices and methods of use
US11135360B1 (en) 2020-12-07 2021-10-05 Icu Medical, Inc. Concurrent infusion with common line auto flush
JP1697125S (en) * 2020-12-28 2021-10-18
JP1701102S (en) * 2020-12-28 2021-11-29
JP1697127S (en) * 2020-12-28 2021-10-18
JP1697126S (en) * 2020-12-28 2021-10-18
JP1701019S (en) * 2020-12-28 2021-11-29
JP1701103S (en) * 2020-12-28 2021-11-29
US11796367B2 (en) 2021-05-07 2023-10-24 Analog Devices, Inc. Fluid control system
CN113975481A (en) * 2021-10-29 2022-01-28 首都医科大学宣武医院 Drainage monitoring system
CN114428522B (en) * 2022-01-29 2023-12-19 湖南比扬医疗科技有限公司 Flow control method and device and infusion pump
CN116983504A (en) * 2022-04-26 2023-11-03 深圳硅基传感科技有限公司 Medical device and medical system for delivering fluids
US20240035465A1 (en) * 2022-07-26 2024-02-01 Brian S. Whitmore Modular Metering Pump System
CN117122771A (en) * 2023-10-27 2023-11-28 中国人民解放军总医院第四医学中心 Flow-control type infusion assembly

Citations (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4018362A (en) * 1975-11-06 1977-04-19 Union Chimique Continentale-U.C.C. Automatic control for liquid flow
US4498843A (en) * 1982-08-02 1985-02-12 Schneider Philip H Insulin infusion pump
US4838860A (en) * 1987-06-26 1989-06-13 Pump Controller Corporation Infusion pump
US4911010A (en) * 1988-08-12 1990-03-27 Flowdata, Inc. Fluid flowmeter
US4919596A (en) * 1987-12-04 1990-04-24 Pacesetter Infusion, Ltd. Fluid delivery control and monitoring apparatus for a medication infusion system
US5009251A (en) * 1988-11-15 1991-04-23 Baxter International, Inc. Fluid flow control
US5150612A (en) * 1990-10-16 1992-09-29 Lew Hyok S Dual revolving vane pump-motor-meter
US5184519A (en) * 1990-10-18 1993-02-09 Illinois Tool Works, Inc. High resolution flow meter
US5190522A (en) * 1989-01-20 1993-03-02 Institute Of Biocybernetics And Biomedical Engineering P.A.S. Device for monitoring the operation of a delivery system and the method of use thereof
US5205819A (en) * 1989-05-11 1993-04-27 Bespak Plc Pump apparatus for biomedical use
US5256156A (en) * 1991-01-31 1993-10-26 Baxter International Inc. Physician closed-loop neuromuscular blocking agent system
US5275043A (en) * 1992-11-19 1994-01-04 Cotton Galen M Positive displacement flowmeter
US5284053A (en) * 1992-01-10 1994-02-08 The Boc Group, Inc. Controlled flow volumetric flowmeter
US5325715A (en) * 1989-08-09 1994-07-05 Flowdata, Inc. Fluid flowmeter
US5370612A (en) * 1992-04-03 1994-12-06 Sharp Kabushiki Kaisha Infusion apparatus capable of measuring a fluid delivery rate taking a dead band into account
US5415041A (en) * 1994-01-24 1995-05-16 Flowdata, Inc. Double helical flowmeter
US5482841A (en) * 1994-05-24 1996-01-09 Sangstat Medical Corporation Evaluation of transplant acceptance
US5533981A (en) * 1994-10-06 1996-07-09 Baxter International Inc. Syringe infusion pump having a syringe plunger sensor
US5533412A (en) * 1993-07-07 1996-07-09 Ic Sensors, Inc. Pulsed thermal flow sensor system
US5658515A (en) * 1995-09-25 1997-08-19 Lee; Abraham P. Polymer micromold and fabrication process
US5681285A (en) * 1992-10-15 1997-10-28 Baxter International Inc. Infusion pump with an electronically loadable drug library and a user interface for loading the library
US5807321A (en) * 1995-11-28 1998-09-15 Merit Medical System for electronically monitoring the delivery of contrast media
US5820589A (en) * 1996-04-30 1998-10-13 Medtronic, Inc. Implantable non-invasive rate-adjustable pump
US5922230A (en) * 1996-03-08 1999-07-13 Eightech Tectron Co., Ltd. Automatic reflow soldering apparatus
US5927547A (en) * 1996-05-31 1999-07-27 Packard Instrument Company System for dispensing microvolume quantities of liquids
US5993420A (en) * 1995-03-06 1999-11-30 Sabratek Corporation Cassette for an infusion pump
US6050143A (en) * 1998-10-21 2000-04-18 Dresser Industries, Inc. Fluid flow system and method for sensing fluid flow
US6063052A (en) * 1993-10-28 2000-05-16 Medrad, Inc. Injection system and pumping system for use therein
US6078273A (en) * 1996-10-29 2000-06-20 Baxter International Inc. Infusion pump monitoring encoder/decoder
US6109878A (en) * 1998-04-13 2000-08-29 Micropump, Inc. System and a method for velocity modulation for pulseless operation of a pump
US6122605A (en) * 1997-07-08 2000-09-19 Johnson Controls Technology Company Apparatus and method for filtering a digital signal
US6203759B1 (en) * 1996-05-31 2001-03-20 Packard Instrument Company Microvolume liquid handling system
US6250151B1 (en) * 1995-10-30 2001-06-26 Marconi Commerce Systems Gmbh & Co. Kg Fluid flow meter incorporating magnetic detector
US6366840B1 (en) * 1997-12-01 2002-04-02 Daimlerchrysler Corporation Vehicle instrument panel wireless communication
US20030072647A1 (en) * 2001-10-11 2003-04-17 Paul Lum Micro paddle wheel pump for precise pumping, mixing, dispensing, and valving of blood and reagents
US20030073954A1 (en) * 2000-03-29 2003-04-17 Minimed Inc. Methods, apparatuses, and uses for infusion pump fluid pressure and force detection
US20030078534A1 (en) * 1998-04-10 2003-04-24 Mark Hochman Drug delivery system with profiles
US20030171710A1 (en) * 2001-05-07 2003-09-11 Bassuk William K. Remote controlled transdermal medication delivery device
US20030171711A1 (en) * 2002-03-06 2003-09-11 Rohr William L. Closed-loop drug delivery system
US6740059B2 (en) * 2000-09-08 2004-05-25 Insulet Corporation Devices, systems and methods for patient infusion
US6802811B1 (en) * 1999-09-17 2004-10-12 Endoluminal Therapeutics, Inc. Sensing, interrogating, storing, telemetering and responding medical implants

Family Cites Families (301)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5338157B1 (en) * 1992-09-09 1999-11-02 Sims Deltec Inc Systems and methods for communicating with ambulat
US2383226A (en) * 1943-09-20 1945-08-21 John A Swindle Liquid meter
FR1299719A (en) 1961-06-16 1962-07-27 Citroen Sa Andre Flow regulator in particular for hydraulic circuit
US3316902A (en) * 1963-03-25 1967-05-02 Tri Tech Monitoring system for respiratory devices
JPS5022064B1 (en) * 1966-07-22 1975-07-28
US3556129A (en) * 1967-04-27 1971-01-19 Richard J Brown Two-stage fluid fuel control valve
US3590886A (en) 1967-08-21 1971-07-06 Whessoe Ltd Liquid flow control valves
US3630496A (en) 1968-01-26 1971-12-28 Babcock & Wilcox Co Gas-cleaning apparatus
GB1248614A (en) 1968-10-02 1971-10-06 Nat Res Dev Apparatus for the conveyance of cohesive particulate material
US3640277A (en) * 1968-12-09 1972-02-08 Marvin Adelberg Medical liquid administration device
US3604386A (en) 1968-12-30 1971-09-14 Filotecnica Salmoiraghi Spa Automatic installation for the transversal balancing of a ship
JPS5118642B1 (en) 1969-01-29 1976-06-11
US3598321A (en) 1969-01-31 1971-08-10 Delavan Manufacturing Co Leaf spring nozzle flow control
JPS5034250B1 (en) * 1969-04-01 1975-11-07
US3655296A (en) * 1969-07-18 1972-04-11 Dems Engineering Co Liquid pump
US3610535A (en) 1969-09-03 1971-10-05 Mite Corp Liquids mixing and selective delivery system
SE336307B (en) 1970-02-16 1971-06-28 Dopslaff Kg J
US3677248A (en) 1970-08-27 1972-07-18 American Hospital Supply Corp Surgical irrigation apparatus and method of using same
US3667464A (en) 1970-09-04 1972-06-06 Lawrence M Alligood Jr Fluid dispensing device
US3790042A (en) 1970-09-15 1974-02-05 Pelam Inc Apparatus for regulating the amount of liquid administered per unit time
US3695004A (en) 1970-10-27 1972-10-03 Arco Ind Corp Gas cleaning system
US3786649A (en) * 1970-11-27 1974-01-22 Patterson Kelley Co Water chiller and storage system
US3790105A (en) 1971-03-08 1974-02-05 K Eickman Hydraulically controlled fluid stream driven vehicle
US3692050A (en) 1971-05-10 1972-09-19 Red Jacket Mfg Co Apparatus for detecting leaks in a fluid delivery line
US3884453A (en) 1971-12-14 1975-05-20 Pennsylvania Engineering Corp Bottom blown steel converter and means for controlling injection of powdered material with process gasses therein
IT947399B (en) 1972-02-08 1973-05-21 Alfa Romeo Spa DEVICE FOR REGULATING THE FLOW OF AIR INSUFFLED IN THE EXHAUST DUCT OF A COMBUSTION ENGINE
US3817261A (en) 1972-05-09 1974-06-18 L Rogge Grain moisturizer
US3785459A (en) * 1972-05-11 1974-01-15 Allis Chalmers Lubrication and cooling system for connecting rod and piston
US3794245A (en) * 1972-05-26 1974-02-26 Williamson Built Inc Intermittent sprinkler and system
US3807446A (en) * 1972-06-05 1974-04-30 Battelle Development Corp Respirator system
SE380610B (en) * 1972-08-22 1975-11-10 Danfoss As VALVE COMBINATION FOR AN OIL POWER PLANT
US3782880A (en) * 1972-09-20 1974-01-01 Gulf Oil Corp Control system to automatically maintain a smokeless flare
US3817246A (en) 1972-12-11 1974-06-18 Puritan Bennett Corp Flow responsive respiration apparatus
US3841438A (en) 1972-12-15 1974-10-15 Watts Regulator Co Injection lubricator
US3797492A (en) * 1972-12-27 1974-03-19 Alza Corp Device for dispensing product with directional guidance member
US3853144A (en) 1973-03-09 1974-12-10 Univ Southern California Flowmeter
US3842720A (en) 1973-03-29 1974-10-22 Piper Aircraft Corp Jet pump for aircraft cabin pressurization system
US3880963A (en) * 1973-04-02 1975-04-29 Colt Ind Operating Corp Method and apparatus for varying fuel flow to compensate for changes in operating temperature
US3846052A (en) 1973-08-08 1974-11-05 Gen Motors Corp Metering pump
US3905362A (en) 1973-10-02 1975-09-16 Chemetron Corp Volume-rate respirator system and method
FR2253389A5 (en) 1973-12-04 1975-06-27 France Etat
US3929157A (en) 1974-06-17 1975-12-30 Juan R Serur Fluid flow regulator
US3910311A (en) 1974-08-26 1975-10-07 Koehring Co Pressure compensated control valve
DE2651722A1 (en) * 1975-11-13 1977-06-08 Regamey Pierre E METHOD AND DEVICE FOR FEEDING A PLANT FOR GENERATING AND DISTRIBUTING A STEAM THAT CAN BE CONDENSED TO FORM A SUPPLEMENTARY LIQUID
GB1581640A (en) 1976-08-17 1980-12-17 English Clays Lovering Pochin System for pumping an abrasive or corrosive fluid
IL65024A (en) * 1976-10-27 1989-07-31 Bron Dan Intravenous infusion set
US4356934A (en) 1977-11-18 1982-11-02 Chevron Research Company Apparatus for spray-treating seeds during planting
US4318214A (en) 1978-07-10 1982-03-09 Colt Industries Operating Corp Method and apparatus for manufacturing and forming engine induction passage venturi
US4306441A (en) 1978-07-10 1981-12-22 Colt Industries Operating Corp Method and apparatus for manufacturing and forming engine induction passage venturi
GB2029903B (en) 1978-09-15 1982-12-15 Plessey Co Ltd Gear pump with pressure loadrd plate
US4275480A (en) 1979-02-21 1981-06-30 Baxter Travenol Laboratories, Inc. Electronic injection metering and monitoring system
US4315754A (en) 1979-08-28 1982-02-16 Bifok Ab Flow injection analysis with intermittent flow
US4295364A (en) 1979-09-07 1981-10-20 Creative Tool Company Transducer device for monitoring of fuel injection
JPS56139316A (en) 1980-01-07 1981-10-30 Komatsu Ltd Power loss reduction controller for oil-pressure type construction machine
CA1156533A (en) * 1980-05-01 1983-11-08 Henry G. Horsewell Smoking articles
US4340355A (en) 1980-05-05 1982-07-20 Honeywell Inc. Furnace control using induced draft blower, exhaust gas flow rate sensing and density compensation
US4368688A (en) * 1980-06-20 1983-01-18 Hauni-Werke Korber & Co. Kg Apparatus for applying liquid plasticizer to filamentary filter material
US4350301A (en) 1980-06-25 1982-09-21 The Bendix Corporation Flow controlled pressure regulating device
US4347824A (en) 1980-06-26 1982-09-07 I.C.E. Company, Inc. LPG Fuel supply system
US4313499A (en) * 1980-07-21 1982-02-02 Gulf Research & Development Company Subterranean gasification of bituminous coal
US4296809A (en) 1980-07-21 1981-10-27 Gulf Research & Development Company In situ gasification of bituminous coal
US4328820A (en) 1980-10-20 1982-05-11 Serur Juan R Constant-flow regulator for gravity-fed liquids
JPS5771728A (en) * 1980-10-21 1982-05-04 Japax Inc Fine hole perforator
DE3047158A1 (en) 1980-12-15 1982-07-22 Egon 5650 Solingen Evertz METHOD AND DEVICE FOR REMOVING SURFACE TREATMENT OF OBJECTS MADE OF HIGH-CARBONIC IRON
US4340050A (en) 1980-12-29 1982-07-20 Delmed Inc. Medical fluid flow rate indicating/controlling device
US4375813A (en) 1981-02-10 1983-03-08 Delmed, Inc. Medical fluid flow rate controlling device
US4438507A (en) 1981-02-12 1984-03-20 Ricoh Co., Ltd. Input signal control device
FR2500086A1 (en) * 1981-02-13 1982-08-20 Laguilharre Pierre INSTALLATION FOR REALIZING A HIGH PRESSURE DIFFERENCE BETWEEN TWO POINTS, USING A SIMPLE FLOOR LIQUID RING PUMP ASSOCIATED WITH A LIQUID FLUID EJECTOR
DE3113028C2 (en) 1981-04-01 1983-10-13 Gkss - Forschungszentrum Geesthacht Gmbh, 2054 Geesthacht Device for the surface treatment of underwater structures and ships
US4431425A (en) * 1981-04-28 1984-02-14 Quest Medical, Inc. Flow fault sensing system
US4857052A (en) 1981-07-13 1989-08-15 Alza Corporation Intravenous system for delivering a beneficial agent
US4511353A (en) 1981-07-13 1985-04-16 Alza Corporation Intravenous system for delivering a beneficial agent
US4985017A (en) 1981-07-13 1991-01-15 Alza Corporation Parenteral therapeutical system comprising drug cell
US4552555A (en) 1981-07-31 1985-11-12 Alza Corporation System for intravenous delivery of a beneficial agent
US4994031A (en) * 1981-07-13 1991-02-19 Alza Corporation Intravenous system for delivering a beneficial agent
USRE34365E (en) 1981-07-13 1993-08-31 Intravenous system for delivering a beneficial agent
US4387734A (en) 1981-07-16 1983-06-14 American Hospital Supply Corporation Apparatus and method for spontaneous meniscus generation
US4871360A (en) 1981-07-31 1989-10-03 Alza Corporation System for intravenous delivery of a beneficial drug at a regulated rates
US4478041A (en) 1981-08-20 1984-10-23 Sundstrand Corporation Hydraulic motor control
US4396002A (en) 1981-08-24 1983-08-02 Lipets Adolf U Tubular air heater
JPS5836562A (en) 1981-08-28 1983-03-03 テルモ株式会社 Control apparatus for drip amount
DE3137562C1 (en) 1981-09-22 1983-03-31 Volkswagenwerk Ag, 3180 Wolfsburg Process for testing a carburetor
US4431020A (en) 1981-10-08 1984-02-14 Marotta Scientific Controls, Inc. Flow-control system having a wide range of flow-rate control
US4586922A (en) 1981-10-09 1986-05-06 Alza Corporation Intravenous system for delivering a beneficial agent
US4474309A (en) 1981-10-22 1984-10-02 Oximetrix, Inc. Stepping motor control procedure for achieving variable rate, quasi-continuous fluid infusion
US4411935A (en) 1981-11-02 1983-10-25 Anderson James Y Powder flame spraying apparatus and method
US4470758A (en) 1981-11-12 1984-09-11 Oximetrix, Inc. Intravenous fluid pump monitor
US4510963A (en) * 1982-01-15 1985-04-16 Electro-Hydraulic Controls, Inc. Proportional-flow electrohydraulic control
US4468220A (en) 1982-04-05 1984-08-28 Milliken Research Corporation Low flow constant rate pump
US4468440A (en) 1982-05-21 1984-08-28 General Electric Company Air heating and cooling system for aircraft batteries
US4459982A (en) 1982-09-13 1984-07-17 Bear Medical Systems, Inc. Servo-controlled demand regulator for respiratory ventilator
US4447224A (en) 1982-09-20 1984-05-08 Infusaid Corporation Variable flow implantable infusion apparatus
US4552017A (en) 1982-11-08 1985-11-12 Metal Improvement Company, Inc. Apparatus for measuring flow-rate of electromagnetic granular media
US4564331A (en) * 1983-01-17 1986-01-14 Karr Ake Wendell Robot
US4477231A (en) 1983-03-17 1984-10-16 Swift Joseph E Variable displacement vane type pump
US4493303A (en) 1983-04-04 1985-01-15 Mack Trucks, Inc. Engine control
DK345883D0 (en) 1983-07-28 1983-07-28 Nordisk Ventilator axial
US4574827A (en) 1983-09-29 1986-03-11 Exxon Production Research Co. Method and apparatus for splitting two-phase flow at pipe tees
US4522218A (en) 1983-09-29 1985-06-11 Exxon Production Research Co. Method and apparatus for splitting two-phase flow at pipe tees
US4543044A (en) 1983-11-09 1985-09-24 E. I. Du Pont De Nemours And Company Constant-flow-rate dual-unit pump
GB8422876D0 (en) 1984-09-11 1984-10-17 Secr Defence Silicon implant devices
DE3447709C1 (en) 1984-12-28 1986-04-30 Karl 7298 Loßburg Hehl Control device for the hydraulic circuit of a plastic injection molding machine
NL8500673A (en) 1985-03-11 1986-10-01 Hoogovens Groep Bv METHOD FOR OPERATING A GAS RECOVERY SYSTEM.
US4612964A (en) 1985-04-01 1986-09-23 Westmont, Inc. Combined auger and air-type valve bag filling machine
US4646568A (en) * 1985-05-06 1987-03-03 Lew Hyok S Flap pump-flow meter
FR2587086B1 (en) 1985-09-10 1988-06-10 Inf Milit Spatiale Aeronaut OPTIMIZED MANAGEMENT METHOD FOR A PIPE-LINES NETWORK AND NETWORK THUS PROVIDED
US4838020A (en) 1985-10-24 1989-06-13 Mitsubishi Denki Kabushiki Kaisha Turbocompressor system and method for controlling the same
US4793807A (en) 1986-02-07 1988-12-27 National Patent Dental Products, Inc. Method for supplying a heated liquid
US4941809A (en) 1986-02-13 1990-07-17 Pinkerton Harry E Valveless positive displacement metering pump
DE3611841A1 (en) * 1986-04-09 1987-10-15 Bayer Ag METHOD FOR PRODUCING 1-DESOXYNOJIRIMYCIN AND ITS N-DERIVATIVES
US4932402A (en) 1986-04-11 1990-06-12 Puritan-Bennett Corporation Inspiration oxygen saver
US4813937A (en) 1986-05-07 1989-03-21 Vaillancourt Vincent L Ambulatory disposable infusion delivery system
US4926852B1 (en) 1986-06-23 1995-05-23 Univ Johns Hopkins Medication delivery system phase one
US4773900A (en) 1986-08-20 1988-09-27 Cochran Ulrich D Infusion device
US4865088A (en) 1986-09-29 1989-09-12 Vacuum Barrier Corporation Controller cryogenic liquid delivery
US5318539A (en) 1986-10-17 1994-06-07 Alexander G. B. O'Neil Liquid feeding apparatus utilizing capillary tubing, and syringe driver
US4828705A (en) 1986-10-31 1989-05-09 Kingston Technologies, Inc. Pressure-dependent anisotropic-transport membrane system
US4782608A (en) 1986-11-07 1988-11-08 Black & Decker, Inc. Variable steam control for electric iron
US4867743A (en) 1986-11-24 1989-09-19 Vaillancourt Vincent L Ambulatory disposable infusion delivery system
US4936832A (en) 1986-11-24 1990-06-26 Vaillancourt Vincent L Ambulatory disposable infusion delivery system
US4867063A (en) 1986-11-25 1989-09-19 Gerald Baker Method and apparatus for dispensing powder in a printing press
FR2609286B1 (en) 1987-01-05 1989-03-17 Atochem CONTINUOUS PROCESS FOR THE PREPARATION OF CARBON POLYMONOFLUORIDE AND APPARATUS FOR IMPLEMENTING SAME
US4802650A (en) 1987-06-29 1989-02-07 Abiomed, Inc. Intravenous drug mixing and flow device
US4755172A (en) 1987-06-30 1988-07-05 Baldwin Brian E Syringe holder/driver and syringe arrangement and syringe/holder driver therefor
US4863429A (en) 1987-06-30 1989-09-05 Baldwin Brian E Syringe driver/syringe/tube connecting set fluid delivery arrangement, and tube connecting sets therefor
US4838257A (en) 1987-07-17 1989-06-13 Hatch Guy M Ventilator
US4966691A (en) 1987-07-20 1990-10-30 Brous Donald W Measurement and control of ultrafiltration in dialysis
US4754603A (en) 1987-07-20 1988-07-05 Rosman Allan H Hydraulic-drive system for an intermittent-demand load
US5207642A (en) 1987-08-07 1993-05-04 Baxter International Inc. Closed multi-fluid delivery system and method
US4925444A (en) 1987-08-07 1990-05-15 Baxter Travenol Laboratories, Inc. Closed multi-fluid delivery system and method
US4938212A (en) 1987-10-16 1990-07-03 Puritan-Bennett Corporation Inspiration oxygen saver
US4836157A (en) 1987-11-09 1989-06-06 Walbro Corporation Cold-start engine priming and air purging system
US4828218A (en) 1987-12-02 1989-05-09 Ransburg Corporation Multiple mode regulator
IT1221912B (en) 1987-12-09 1990-07-12 Weber Srl VARIABLE DISPLACEMENT FUEL INJECTION PUMP FOR DIESEL ENGINE INJECTION EQUIPMENT
US5617456A (en) * 1988-01-14 1997-04-01 Hitachi, Ltd. Fuel assembly and nuclear reactor
US5640435A (en) 1988-01-14 1997-06-17 Hitachi, Ltd. Fuel assembly and nuclear reactor
GB8802091D0 (en) 1988-01-30 1988-02-24 Lucas Ind Plc Improvements in hydraulic anti-lock braking systems for vehicles
GB8803380D0 (en) 1988-02-13 1988-03-16 Gbe International Plc Rotary drier control by adjustment of air flow/air humidity
US4790349A (en) 1988-04-04 1988-12-13 Stant Inc. Tank pressure control system
US5730731A (en) 1988-04-28 1998-03-24 Thomas J. Fogarty Pressure-based irrigation accumulator
US4875840A (en) 1988-05-12 1989-10-24 Tecumseh Products Company Compressor lubrication system with vent
US4932232A (en) 1988-05-20 1990-06-12 Alcan Aluminum Corporation Methods of detecting and correcting spray header malfunctions
US5325668A (en) 1988-06-10 1994-07-05 S.I.T.I. Societa Impianti Termoelettrici Industriali S.P.A. Method and apparatus for hydraulic pressing
US5064119A (en) 1989-02-03 1991-11-12 Binks Manufacturing Company High-volume low pressure air spray gun
US4985016A (en) 1989-02-15 1991-01-15 Alza Corporation Intravenous system for delivering a beneficial agent
US4969871A (en) 1989-02-15 1990-11-13 Alza Corporation Intravenous system for delivering a beneficial agent
US5250028A (en) 1989-02-15 1993-10-05 Alza Corporation Intravenous system for delivering a beneficial agent using permeability enhancers
US4979644A (en) 1989-02-15 1990-12-25 Quest Medical Inc. Rate-controlled gravity drip delivery apparatus
US4969872A (en) 1989-03-08 1990-11-13 Alza Corporation Intravenous system for delivering a beneficial agent with delivery rate control via permeable surface area variance
AU635262B2 (en) 1989-05-11 1993-03-18 Bespak Plc Pump apparatus for biomedical use
JPH0324090A (en) * 1989-06-21 1991-02-01 Toray Dow Corning Silicone Co Ltd Organosilicon compound and production thereof
US5061242A (en) 1989-07-18 1991-10-29 Infusaid, Inc. Adjustable implantable drug infusion system
US4921547A (en) 1989-07-26 1990-05-01 Vickers Incorporated Proportional priority flow regulator
US5019055A (en) 1989-12-22 1991-05-28 Boyle Matthew O Flow regulator and method
IL93255A (en) 1990-02-02 1997-03-18 Plastro Gvat Drip irrigation lines
US4972878A (en) 1990-02-12 1990-11-27 Jack Carlin Firetruck valve
US5219279A (en) 1990-03-15 1993-06-15 Abbott Laboratories Volumetric pump with pump plunger support and method
US5055001A (en) 1990-03-15 1991-10-08 Abbott Laboratories Volumetric pump with spring-biased cracking valves
GB9007020D0 (en) * 1990-03-29 1990-05-30 Fxk Patents Ltd Emergency breathing equipment
US5492534A (en) 1990-04-02 1996-02-20 Pharmetrix Corporation Controlled release portable pump
US5318540A (en) 1990-04-02 1994-06-07 Pharmetrix Corporation Controlled release infusion device
US5234265A (en) 1990-04-06 1993-08-10 G. W. Lisk Company, Inc. Valve for automatic brake system
US5672167A (en) 1990-05-21 1997-09-30 Recordati Corporation Controlled release osmotic pump
US5257987A (en) 1990-05-21 1993-11-02 Pharmetrix Corporation Controlled release osmotic infusion system
US5220517A (en) 1990-08-31 1993-06-15 Sci Systems, Inc. Process gas distribution system and method with supervisory control
US5232434A (en) 1990-10-05 1993-08-03 Aisin Seiki Kabushiki Kaisha Fluid feeding pump unit
GB9104097D0 (en) * 1991-02-27 1991-04-17 Univ Hospital London Dev Corp Computer controlled positive displacement pump for physiological flow stimulation
US5450336A (en) 1991-03-05 1995-09-12 Aradigm Corporation Method for correcting the drift offset of a transducer
DE9218858U1 (en) 1991-05-16 1995-12-07 Sandoz Ag Double piston pump
US5279607A (en) * 1991-05-30 1994-01-18 The State University Of New York Telemetry capsule and process
US5205722A (en) 1991-06-04 1993-04-27 Hammond John M Metering pump
US5368451A (en) 1991-06-04 1994-11-29 Hammond; John M. Metering pump
JPH07112836B2 (en) 1991-06-14 1995-12-06 富士重工業株式会社 Aircraft hydraulic steering system
US5402777A (en) 1991-06-28 1995-04-04 Alza Corporation Methods and devices for facilitated non-invasive oxygen monitoring
US5251149A (en) 1991-08-02 1993-10-05 Great Plains Industries, Inc. Electronic nutating disc flow meter
FR2682164B1 (en) 1991-10-07 1995-01-20 Cit Alcatel GAS PUMPING INSTALLATION WITH PUMPING SPEED REGULATION.
US5186057A (en) 1991-10-21 1993-02-16 Everhart Howard R Multi-beam liquid-drop size/rate detector apparatus
US5179975A (en) * 1991-10-24 1993-01-19 Jim Stevenson Chemical mixing and delivery system
US5624509A (en) * 1991-12-23 1997-04-29 Stanley; Corby H. Wheel traction device
US5251785A (en) 1992-02-06 1993-10-12 The Lubrizol Corporation Additive injection system and method
DE4206576B4 (en) 1992-03-02 2005-08-04 Putzmeister Ag Method and arrangement for determining the delivery rate or the delivery rate of conveyed material transported by means of a piston-type fuel pump
US5980489A (en) 1992-04-17 1999-11-09 Science Incorporated Fluid dispenser with fill adapter
US6090071A (en) 1992-04-17 2000-07-18 Science Incorporated Fluid dispenser with fill adapter
US5306257A (en) * 1992-05-04 1994-04-26 Prime Medical Products, Inc. Drug infuser
US5246026A (en) 1992-05-12 1993-09-21 Proudman Systems, Inc. Fluid measuring, dilution and delivery system
US5218945A (en) 1992-06-16 1993-06-15 Gas Research Institute Pro-active control system for a heat engine
EP0586740B1 (en) 1992-09-11 1996-12-18 Siemens-Elema AB Device for preventing passage of air bubbles
US5314100A (en) 1992-09-25 1994-05-24 Deaver Jim D Grout delivery system
EP0662844B1 (en) 1992-10-01 1998-03-11 American Sterilizer Company Accumulator-based liquid metering system and method
FR2698666B1 (en) 1992-11-30 1995-02-17 Europ Propulsion High performance centrifugal pump with open impeller.
US5356076A (en) 1993-03-29 1994-10-18 Bishop Robert A Shower soap dispenser for liquid soaps
DE4312419C2 (en) 1993-04-16 1996-02-22 Reifenhaeuser Masch Plant for the production of a spunbonded nonwoven web from aerodynamically stretched plastic filaments
ATE182400T1 (en) 1993-05-17 1999-08-15 Danieli Off Mecc ARC FURNACE WITH DIFFERENT ENERGY SOURCES AND PROCESSES FOR ITS OPERATION
US5417213A (en) 1993-06-07 1995-05-23 Prince; Martin R. Magnetic resonance arteriography with dynamic intravenous contrast agents
US5411474A (en) 1993-07-14 1995-05-02 Douglas E. Ott Method and apparatus for conditioning insufflation gas for laparoscopic surgery
FR2708991B1 (en) 1993-08-10 1995-09-15 Cerga Method and device for supplying ventilation air to the different rooms of a room.
US5348231A (en) 1993-10-05 1994-09-20 Arnold Don C Two-stage aerator
DE4335328A1 (en) 1993-10-18 1995-04-20 Battenfeld Gmbh Hydraulic operating system for injection molding machines
US5957672A (en) * 1993-11-10 1999-09-28 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Blood pump bearing system
US5839434A (en) 1993-11-16 1998-11-24 Invacare Corporation Method and apparatus for dispensing respiratory gases
US5474054A (en) 1993-12-27 1995-12-12 Ford Motor Company Fuel injection control system with compensation for pressure and temperature effects on injector performance
SE502222C2 (en) 1994-01-17 1995-09-18 Althin Medical Ab Method of dialysis
US5411059A (en) 1994-02-01 1995-05-02 Essex Industries, Inc. Multiple flow rate fluid control valve assembly
JP3111790B2 (en) 1994-02-03 2000-11-27 株式会社日立製作所 Flow control pump
US5751300A (en) 1994-02-04 1998-05-12 Hewlett-Packard Company Ink delivery system for a printer
US5492724A (en) 1994-02-22 1996-02-20 Osram Sylvania Inc. Method for the controlled delivery of vaporized chemical precursor to an LPCVD reactor
US5437629A (en) 1994-04-14 1995-08-01 Bei Medical Systems Fluid delivery system for hysteroscopic endometrial ablation
CH689124A5 (en) 1994-04-18 1998-10-15 Miteco Ag Means for Over guards a flow rate of a Liquid.
US5460490A (en) 1994-05-19 1995-10-24 Linvatec Corporation Multi-purpose irrigation/aspiration pump system
US5509791A (en) * 1994-05-27 1996-04-23 Turner; Ogden L. Variable delivery pump for molten metal
US5665640A (en) 1994-06-03 1997-09-09 Sony Corporation Method for producing titanium-containing thin films by low temperature plasma-enhanced chemical vapor deposition using a rotating susceptor reactor
US5624409A (en) 1994-06-10 1997-04-29 Fluidsense Corporation Variable-pulse dynamic fluid flow controller
US5447586A (en) 1994-07-12 1995-09-05 E. I. Du Pont De Nemours And Company Control of thermoplastic tow placement
US5478505A (en) 1994-07-14 1995-12-26 Jim F. Warner Air treating device
US5504306A (en) * 1994-07-25 1996-04-02 Chronomite Laboratories, Inc. Microprocessor controlled tankless water heater system
US5513636A (en) 1994-08-12 1996-05-07 Cb-Carmel Biotechnology Ltd. Implantable sensor chip
DE4430652C2 (en) * 1994-08-29 1997-01-30 Metallglanz Gmbh Galvanic method and device for carrying out the method and its use for galvanic or chemical treatment, in particular for the continuous application of metallic layers to a body
DE4434190C2 (en) 1994-09-24 1997-05-28 Heidelberger Druckmasch Ag Sheet delivery on a sheet processing machine
US5620143A (en) 1994-10-24 1997-04-15 Drip Tape Manufacturers & Engineers, Inc. Constant-flow irrigation tape and method of making
US5785785A (en) 1994-10-24 1998-07-28 Drip Tape Manufacturers & Engineers, Inc. Method of making constant flow irrigation tape
JPH08133058A (en) 1994-11-11 1996-05-28 Toyota Motor Corp Brake system
JP3521981B2 (en) 1994-11-28 2004-04-26 株式会社小松製作所 Construction machine traction force control device and control method thereof
US5620524A (en) 1995-02-27 1997-04-15 Fan; Chiko Apparatus for fluid delivery in chemical vapor deposition systems
AT1628U1 (en) 1995-03-30 1997-08-25 Avl Verbrennungskraft Messtech INJECTION DEVICE FOR AN INTERNAL COMBUSTION ENGINE WITH DIRECT INJECTION
ES2187647T3 (en) * 1995-03-27 2003-06-16 Zevex Inc PELLIZCO CLAMP OBSTRUCTION DEVICE FOR PERFUSERS.
US6142979A (en) 1995-03-27 2000-11-07 Zevex Pinch clip occluder system for infusion sets
US5683149A (en) 1995-04-05 1997-11-04 Toyota Jidosha Kabushiki Kaisha Hydraulic pressure control apparatus having device for estimating amount of fluid in reservoir to which the fluid is discharged to reduce cylinder pressure
US5566660A (en) 1995-04-13 1996-10-22 Caterpillar Inc. Fuel injection rate shaping apparatus for a unit fuel injector
US5632444A (en) 1995-04-13 1997-05-27 Caterpillar Inc. Fuel injection rate shaping apparatus for a unit injector
JPH08309599A (en) 1995-05-23 1996-11-26 Kyoichi Sato Ram driving controller for hydraulic press and driving control method for the same
US5557935A (en) 1995-05-23 1996-09-24 Kelsey-Hayes Company Apply-rate-independent fast-fill master cylinder
US5648052A (en) 1995-05-30 1997-07-15 Martin Marietta Corporation Liquid monopropellant gas generator
US5779451A (en) 1995-06-05 1998-07-14 Hatton; Gregory John Power efficient multi-stage twin screw pump
US5735268A (en) 1995-06-07 1998-04-07 Salter Labs Intermitten gas-insufflation apparatus and method therefor
US5697364A (en) 1995-06-07 1997-12-16 Salter Labs Intermittent gas-insufflation apparatus
US5722956A (en) 1995-08-24 1998-03-03 The General Hospital Corporation Multi-dose syringe driver
JP3511425B2 (en) 1995-09-18 2004-03-29 日立建機株式会社 Hydraulic system
US5694764A (en) 1995-09-18 1997-12-09 Sundstrand Corporation Fuel pump assist for engine starting
US5628305A (en) 1995-09-27 1997-05-13 Richard J. Melker Universal ventilation device
US5730730A (en) 1995-09-29 1998-03-24 Darling, Jr.; Phillip H. Liquid flow rate control device
US6213986B1 (en) 1995-09-29 2001-04-10 Appro Healthcare, Inc. Liquid flow rate control device
AU7262496A (en) 1995-10-13 1997-04-30 Nordson Corporation Flip chip underfill system and method
US5684245A (en) 1995-11-17 1997-11-04 Mks Instruments, Inc. Apparatus for mass flow measurement of a gas
US5855756A (en) * 1995-11-28 1999-01-05 Bhp Copper Inc. Methods and apparatus for enhancing electrorefining intensity and efficiency
US5807115A (en) 1996-01-31 1998-09-15 Hu; Oliver Yoa-Pu Dissolution apparatus simulating physiological gastrointestinal conditions
US5673562A (en) 1996-02-23 1997-10-07 L'air Liquide, S.A. Bulk delivery of ultra-high purity gases at high flow rates
US5788674A (en) 1996-03-05 1998-08-04 Medication Delivery Devices, Inc. Apparatus and method for limiting free-flow in an infusion system
AU1917797A (en) 1996-03-14 1997-10-01 Alexander George Brian O'neil Patient controllable drug delivery system flow regulating means
US6171298B1 (en) 1996-05-03 2001-01-09 Situs Corporation Intravesical infuser
US5794667A (en) 1996-05-17 1998-08-18 Gilbarco Inc. Precision fuel dispenser
IT1285713B1 (en) 1996-05-20 1998-06-18 Magneti Marelli Spa PROCEDURE FOR CHECKING A NON-RETURN FUEL SYSTEM FOR AN ENDOTHERMIC ENGINE AND
US5775964A (en) 1996-05-31 1998-07-07 Clark; Scott R. Fluid mixer conduit
US5697132A (en) 1996-06-17 1997-12-16 Morganthal Llc System and method for automated mixing and delivery of embalming fluid to a cadaver
US5829108A (en) 1996-06-17 1998-11-03 Morganthal L.P. System and method for automated mixing and delivery of embalming fluid to a cadaver
US5868159A (en) 1996-07-12 1999-02-09 Mks Instruments, Inc. Pressure-based mass flow controller
US5728137A (en) 1996-07-18 1998-03-17 Anderson-Fignon; Karen Liquid dispensing system
US6158965A (en) 1996-07-30 2000-12-12 Alaris Medical Systems, Inc. Fluid flow resistance monitoring system
WO1998006946A1 (en) 1996-08-12 1998-02-19 Hitachi Construction Machinery Co., Ltd. Apparatus for diagnosing failure of hydraulic pump for work machine
JP3901252B2 (en) 1996-08-13 2007-04-04 キヤノンアネルバ株式会社 Chemical vapor deposition equipment
DE59706943D1 (en) 1996-09-09 2002-05-16 Siemens Ag Method and device for controlling a device for distributing items to be sorted to physical target locations
US5724824A (en) 1996-12-12 1998-03-10 Parsons; David A. Evaporative cooling delivery control system
SE9700181D0 (en) 1997-01-22 1997-01-22 Pacesetter Ab Ischemia detector and heart stimulator provided with such an ischemia detector
US6019114A (en) 1997-02-12 2000-02-01 Icon Dynaamics, Llc Self-metering reservoir
US5868179A (en) 1997-03-04 1999-02-09 Gilbarco Inc. Precision fuel dispenser
US6068163A (en) 1997-03-17 2000-05-30 Kihm; Scott C. Fuel dispensing apparatus
US5910135A (en) 1997-03-31 1999-06-08 Innovative Design Associates Intravenous infusion system
US6019115A (en) 1997-12-19 2000-02-01 Sanders Valve Corporation Safety excess flow valve system with adjustable closing flow rate settings
US6085742A (en) 1997-04-02 2000-07-11 Aeromax Technologies, Inc. Intrapulmonary delivery device
US6065694A (en) 1997-04-02 2000-05-23 Staar S.A. Flow limiter
US5794612A (en) 1997-04-02 1998-08-18 Aeromax Technologies, Inc. MDI device with ultrasound sensor to detect aerosol dispensing
JP3587957B2 (en) * 1997-06-12 2004-11-10 日立建機株式会社 Engine control device for construction machinery
US5876675A (en) 1997-08-05 1999-03-02 Caliper Technologies Corp. Microfluidic devices and systems
EP0897690B1 (en) 1997-08-15 2013-04-24 Academisch Ziekenhuis Leiden h.o.d.n. LUMC Pressure sensor for use in an aneurysmal sac
EP1003579B1 (en) 1997-08-22 2005-01-12 Deka Products Limited Partnership System and cassette for mixing and delivering intravenous drugs
US5944255A (en) 1997-08-29 1999-08-31 Shirmohamadi; Manuchehr Shower water automatic temperature controller
US5986680A (en) 1997-08-29 1999-11-16 Eastman Kodak Company Microfluidic printing using hot melt ink
US5827959A (en) 1997-09-18 1998-10-27 Clanin; William B. Monitoring chemical flow rate in a water treatment system
JP3511453B2 (en) 1997-10-08 2004-03-29 日立建機株式会社 Control device for prime mover and hydraulic pump of hydraulic construction machine
US6216690B1 (en) 1997-10-15 2001-04-17 Datex-Ohmeda, Inc. Method and apparatus for rapid control of set inspired gas concentration in anesthesia delivery systems
BR9813287A (en) * 1997-10-27 2000-08-22 Idexx Lab Inc Device and methods for determining analyte in a solution
US5992230A (en) * 1997-11-15 1999-11-30 Hoffer Flow Controls, Inc. Dual rotor flow meter
US5895764A (en) 1997-11-24 1999-04-20 University Of New Mexico Controlled sheath flow injection cytometry
US6293901B1 (en) * 1997-11-26 2001-09-25 Vascor, Inc. Magnetically suspended fluid pump and control system
US5932091A (en) 1998-01-22 1999-08-03 The United States Of America As Represented By The Secretary Of The Navy Oily waste water treatment system
US6203523B1 (en) 1998-02-02 2001-03-20 Medtronic Inc Implantable drug infusion device having a flow regulator
US6169926B1 (en) 1998-02-27 2001-01-02 James A. Baker RF electrode array for low-rate collagen shrinkage in capsular shift procedures and methods of use
US6183461B1 (en) 1998-03-11 2001-02-06 Situs Corporation Method for delivering a medication
US6136725A (en) 1998-04-14 2000-10-24 Cvd Systems, Inc. Method for chemical vapor deposition of a material on a substrate
US6085726A (en) 1998-05-20 2000-07-11 Navistar International Transportation Corp. Fuel injector
US6247061B1 (en) 1998-06-09 2001-06-12 Microsoft Corporation Method and computer program product for scheduling network communication packets originating from different flows having unique service requirements
US5906597A (en) 1998-06-09 1999-05-25 I-Flow Corporation Patient-controlled drug administration device
US6070453A (en) 1998-08-12 2000-06-06 Tokheim Corporation Computerized dispenser tester
US6217659B1 (en) 1998-10-16 2001-04-17 Air Products And Chemical, Inc. Dynamic blending gas delivery system and method
US6235635B1 (en) 1998-11-19 2001-05-22 Chartered Semiconductor Manufacturing Ltd. Linear CMP tool design using in-situ slurry distribution and concurrent pad conditioning
US6202645B1 (en) * 1999-02-25 2001-03-20 Porter Instruments, Inc. Control valve actuated by low-pressure and low-flow rate control fluid
US6349740B1 (en) 1999-04-08 2002-02-26 Abbott Laboratories Monolithic high performance miniature flow control unit
US6135967A (en) 1999-04-26 2000-10-24 Fiorenza; Anthony Joseph Respiratory ventilator with automatic flow calibration
US6073860A (en) 1999-04-30 2000-06-13 Coppock; Craig A. Anti-spilling down flow drinking straw
US6193704B1 (en) 1999-06-10 2001-02-27 Thomas F. Winters Site-specific postoperative pain relief system, fit and method
US6212959B1 (en) * 1999-08-03 2001-04-10 Craig R. Perkins Hydration insuring system comprising liquid-flow meter
US7267661B2 (en) * 2002-06-17 2007-09-11 Iradimed Corporation Non-magnetic medical infusion device

Patent Citations (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4018362A (en) * 1975-11-06 1977-04-19 Union Chimique Continentale-U.C.C. Automatic control for liquid flow
US4498843A (en) * 1982-08-02 1985-02-12 Schneider Philip H Insulin infusion pump
US4838860A (en) * 1987-06-26 1989-06-13 Pump Controller Corporation Infusion pump
US4919596A (en) * 1987-12-04 1990-04-24 Pacesetter Infusion, Ltd. Fluid delivery control and monitoring apparatus for a medication infusion system
US4911010A (en) * 1988-08-12 1990-03-27 Flowdata, Inc. Fluid flowmeter
US5009251A (en) * 1988-11-15 1991-04-23 Baxter International, Inc. Fluid flow control
US5190522A (en) * 1989-01-20 1993-03-02 Institute Of Biocybernetics And Biomedical Engineering P.A.S. Device for monitoring the operation of a delivery system and the method of use thereof
US5205819A (en) * 1989-05-11 1993-04-27 Bespak Plc Pump apparatus for biomedical use
US5325715A (en) * 1989-08-09 1994-07-05 Flowdata, Inc. Fluid flowmeter
US5150612A (en) * 1990-10-16 1992-09-29 Lew Hyok S Dual revolving vane pump-motor-meter
US5184519A (en) * 1990-10-18 1993-02-09 Illinois Tool Works, Inc. High resolution flow meter
US5256156A (en) * 1991-01-31 1993-10-26 Baxter International Inc. Physician closed-loop neuromuscular blocking agent system
US5284053A (en) * 1992-01-10 1994-02-08 The Boc Group, Inc. Controlled flow volumetric flowmeter
US5370612A (en) * 1992-04-03 1994-12-06 Sharp Kabushiki Kaisha Infusion apparatus capable of measuring a fluid delivery rate taking a dead band into account
US5681285A (en) * 1992-10-15 1997-10-28 Baxter International Inc. Infusion pump with an electronically loadable drug library and a user interface for loading the library
US6269340B1 (en) * 1992-10-15 2001-07-31 The General Hospital Infusion pump with an electronically loadable drug library and a user interface for loading the library
US5275043A (en) * 1992-11-19 1994-01-04 Cotton Galen M Positive displacement flowmeter
US5533412A (en) * 1993-07-07 1996-07-09 Ic Sensors, Inc. Pulsed thermal flow sensor system
US6063052A (en) * 1993-10-28 2000-05-16 Medrad, Inc. Injection system and pumping system for use therein
US5415041A (en) * 1994-01-24 1995-05-16 Flowdata, Inc. Double helical flowmeter
US5482841A (en) * 1994-05-24 1996-01-09 Sangstat Medical Corporation Evaluation of transplant acceptance
US5533981A (en) * 1994-10-06 1996-07-09 Baxter International Inc. Syringe infusion pump having a syringe plunger sensor
US5993420A (en) * 1995-03-06 1999-11-30 Sabratek Corporation Cassette for an infusion pump
US5658515A (en) * 1995-09-25 1997-08-19 Lee; Abraham P. Polymer micromold and fabrication process
US6250151B1 (en) * 1995-10-30 2001-06-26 Marconi Commerce Systems Gmbh & Co. Kg Fluid flow meter incorporating magnetic detector
US5807321A (en) * 1995-11-28 1998-09-15 Merit Medical System for electronically monitoring the delivery of contrast media
US5922230A (en) * 1996-03-08 1999-07-13 Eightech Tectron Co., Ltd. Automatic reflow soldering apparatus
US5820589A (en) * 1996-04-30 1998-10-13 Medtronic, Inc. Implantable non-invasive rate-adjustable pump
US5927547A (en) * 1996-05-31 1999-07-27 Packard Instrument Company System for dispensing microvolume quantities of liquids
US6079283A (en) * 1996-05-31 2000-06-27 Packard Instruments Comapny Method for aspirating sample liquid into a dispenser tip and thereafter ejecting droplets therethrough
US6083762A (en) * 1996-05-31 2000-07-04 Packard Instruments Company Microvolume liquid handling system
US6203759B1 (en) * 1996-05-31 2001-03-20 Packard Instrument Company Microvolume liquid handling system
US6078273A (en) * 1996-10-29 2000-06-20 Baxter International Inc. Infusion pump monitoring encoder/decoder
US6122605A (en) * 1997-07-08 2000-09-19 Johnson Controls Technology Company Apparatus and method for filtering a digital signal
US6366840B1 (en) * 1997-12-01 2002-04-02 Daimlerchrysler Corporation Vehicle instrument panel wireless communication
US20030078534A1 (en) * 1998-04-10 2003-04-24 Mark Hochman Drug delivery system with profiles
US6109878A (en) * 1998-04-13 2000-08-29 Micropump, Inc. System and a method for velocity modulation for pulseless operation of a pump
US6050143A (en) * 1998-10-21 2000-04-18 Dresser Industries, Inc. Fluid flow system and method for sensing fluid flow
US6802811B1 (en) * 1999-09-17 2004-10-12 Endoluminal Therapeutics, Inc. Sensing, interrogating, storing, telemetering and responding medical implants
US20030073954A1 (en) * 2000-03-29 2003-04-17 Minimed Inc. Methods, apparatuses, and uses for infusion pump fluid pressure and force detection
US6740059B2 (en) * 2000-09-08 2004-05-25 Insulet Corporation Devices, systems and methods for patient infusion
US20030171710A1 (en) * 2001-05-07 2003-09-11 Bassuk William K. Remote controlled transdermal medication delivery device
US20030072647A1 (en) * 2001-10-11 2003-04-17 Paul Lum Micro paddle wheel pump for precise pumping, mixing, dispensing, and valving of blood and reagents
US20030171711A1 (en) * 2002-03-06 2003-09-11 Rohr William L. Closed-loop drug delivery system

Cited By (73)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10357620B2 (en) 2003-10-02 2019-07-23 Medtronic, Inc. Determining catheter status
US9138537B2 (en) 2003-10-02 2015-09-22 Medtronic, Inc. Determining catheter status
US9033920B2 (en) 2003-10-02 2015-05-19 Medtronic, Inc. Determining catheter status
US7955319B2 (en) 2003-10-02 2011-06-07 Medtronic, Inc. Pressure sensing in implantable medical devices
US20060288803A1 (en) * 2003-11-05 2006-12-28 Agilent Technologies, Inc. Chromatography system with blockage determination
US7278329B2 (en) * 2003-11-05 2007-10-09 Agilent Technologies, Inc. Chromatography system with blockage determination
US10226207B2 (en) 2004-12-29 2019-03-12 Abbott Diabetes Care Inc. Sensor inserter having introducer
US11160475B2 (en) 2004-12-29 2021-11-02 Abbott Diabetes Care Inc. Sensor inserter having introducer
WO2006089965A1 (en) * 2005-02-28 2006-08-31 Novo Nordisk A/S Device for providing a change in a drug delivery rate
US20080147041A1 (en) * 2005-02-28 2008-06-19 Novo Nordisk A/S Device for Providing a Change in a Drug Delivery Rate
US7944366B2 (en) * 2005-09-19 2011-05-17 Lifescan, Inc. Malfunction detection with derivative calculation
US7645238B2 (en) 2005-12-02 2010-01-12 The Cooper Health System Regional anesthetic method and apparatus
US7931594B2 (en) 2005-12-02 2011-04-26 The Cooper Health System Regional anesthetic method and apparatus
WO2007065145A2 (en) * 2005-12-02 2007-06-07 The Cooper Health System Regional anesthetic method and apparatus
WO2007065145A3 (en) * 2005-12-02 2007-11-01 Cooper Health System Regional anesthetic method and apparatus
US8317770B2 (en) 2006-04-06 2012-11-27 Medtronic, Inc. Systems and methods of identifying catheter malfunctions using pressure sensing
US9636450B2 (en) * 2007-02-19 2017-05-02 Udo Hoss Pump system modular components for delivering medication and analyte sensing at seperate insertion sites
US20080200897A1 (en) * 2007-02-19 2008-08-21 Abbott Diabetes Care, Inc. Modular combination of medication infusion and analyte monitoring
US20090012812A1 (en) * 2007-03-06 2009-01-08 Tracy Rausch System and method for patient care
US11291763B2 (en) 2007-03-13 2022-04-05 Tandem Diabetes Care, Inc. Basal rate testing using frequent blood glucose input
US9044537B2 (en) 2007-03-30 2015-06-02 Medtronic, Inc. Devices and methods for detecting catheter complications
US8323244B2 (en) 2007-03-30 2012-12-04 Medtronic, Inc. Catheter malfunction determinations using physiologic pressure
US11257580B2 (en) 2007-05-24 2022-02-22 Tandem Diabetes Care, Inc. Expert system for insulin pump therapy
US11848089B2 (en) 2007-05-24 2023-12-19 Tandem Diabetes Care, Inc. Expert system for insulin pump therapy
US10943687B2 (en) 2007-05-24 2021-03-09 Tandem Diabetes Care, Inc. Expert system for insulin pump therapy
US10357607B2 (en) 2007-05-24 2019-07-23 Tandem Diabetes Care, Inc. Correction factor testing using frequent blood glucose input
US9833177B2 (en) 2007-05-30 2017-12-05 Tandem Diabetes Care, Inc. Insulin pump based expert system
US11298053B2 (en) 2007-05-30 2022-04-12 Tandem Diabetes Care, Inc. Insulin pump based expert system
US11576594B2 (en) 2007-05-30 2023-02-14 Tandem Diabetes Care, Inc. Insulin pump based expert system
US11302433B2 (en) 2008-01-07 2022-04-12 Tandem Diabetes Care, Inc. Diabetes therapy coaching
US10052049B2 (en) 2008-01-07 2018-08-21 Tandem Diabetes Care, Inc. Infusion pump with blood glucose alert delay
AU2009204243B2 (en) * 2008-01-08 2013-01-31 Baxter Healthcare S.A. System and method for detecting occlusion using flow sensor output
US8264363B2 (en) 2008-01-08 2012-09-11 Baxter International Inc. System and method for detecting occlusion using flow sensor output
US20110137241A1 (en) * 2008-01-08 2011-06-09 Baxter International Inc. System and method for detecting occlusion using flow sensor output
EP2277575A1 (en) * 2008-01-08 2011-01-26 Baxter International Inc. System and method for detecting occlusion using flow sensor output
US9889250B2 (en) 2008-01-09 2018-02-13 Tandem Diabetes Care, Inc. Infusion pump with temperature monitoring
US10773015B2 (en) 2008-01-09 2020-09-15 Tandem Diabetes Care, Inc. Infusion pump incorporating information from personal information manager devices
US20110040251A1 (en) * 2008-01-09 2011-02-17 Michael Blomquist Infusion pump with add-on modules
US11850394B2 (en) 2008-01-09 2023-12-26 Tandem Diabetes Care, Inc. Infusion pump with add-on modules
US8840582B2 (en) 2008-01-09 2014-09-23 Tandem Diabetes Care, Inc. Infusion pump with activity monitoring
US8414523B2 (en) * 2008-01-09 2013-04-09 Tandem Diabetes Care, Inc. Infusion pump with add-on modules
US8373421B2 (en) * 2009-04-16 2013-02-12 Roche Diagnostics International Ag Ambulatory infusion device with sensor testing unit
US9222987B2 (en) 2009-04-16 2015-12-29 Roche Diagnostics International Ag Ambulatory infusion device with sensor testing unit
US20100264931A1 (en) * 2009-04-16 2010-10-21 Roche Diagnostics International Ag Ambulatory infusion device with sensor testing unit
US8777897B2 (en) 2009-07-06 2014-07-15 Carefusion 303, Inc. Fluid delivery systems and methods having wireless communication
US10016559B2 (en) 2009-12-04 2018-07-10 Smiths Medical Asd, Inc. Advanced step therapy delivery for an ambulatory infusion pump and system
US11090432B2 (en) 2009-12-04 2021-08-17 Smiths Medical Asd, Inc. Advanced step therapy delivery for an ambulatory infusion pump and system
US9375531B2 (en) * 2011-10-27 2016-06-28 Zyno Medical, Llc Syringe pump with improved flow monitoring
US20130204202A1 (en) * 2012-02-08 2013-08-08 Stmicroelectronics, Inc. Wireless strain gauge/flow sensor
US10434252B2 (en) * 2012-02-08 2019-10-08 Stmicroelectronics, Inc. Wireless strain gauge/flow sensor
US20160129183A1 (en) * 2012-02-08 2016-05-12 Stmicroelectronics, Inc. Wireless strain gauge/flow sensor
US9539389B2 (en) * 2012-02-08 2017-01-10 Stmicroelectronics, Inc. Wireless flow sensor using present flow rate data
US11676694B2 (en) 2012-06-07 2023-06-13 Tandem Diabetes Care, Inc. Device and method for training users of ambulatory medical devices
US10384004B2 (en) * 2013-01-21 2019-08-20 Baxter International Inc. Infusion pump and method to enhance long term medication delivery accuracy
US10357606B2 (en) 2013-03-13 2019-07-23 Tandem Diabetes Care, Inc. System and method for integration of insulin pumps and continuous glucose monitoring
US11607492B2 (en) 2013-03-13 2023-03-21 Tandem Diabetes Care, Inc. System and method for integration and display of data of insulin pumps and continuous glucose monitoring
US10016561B2 (en) 2013-03-15 2018-07-10 Tandem Diabetes Care, Inc. Clinical variable determination
US20150023808A1 (en) * 2013-07-22 2015-01-22 Baxter Healthcare S.A. Infusion pump including reverse loading protection
US10132302B2 (en) * 2013-07-22 2018-11-20 Baxter International Inc. Infusion pump including reverse loading protection
US20150148739A1 (en) * 2013-11-27 2015-05-28 April Marie Radicella Simplified Microplegia Delivery System
US9669160B2 (en) 2014-07-30 2017-06-06 Tandem Diabetes Care, Inc. Temporary suspension for closed-loop medicament therapy
US11638781B2 (en) 2015-12-29 2023-05-02 Tandem Diabetes Care, Inc. System and method for switching between closed loop and open loop control of an ambulatory infusion pump
US10569016B2 (en) 2015-12-29 2020-02-25 Tandem Diabetes Care, Inc. System and method for switching between closed loop and open loop control of an ambulatory infusion pump
US11123477B2 (en) * 2016-09-16 2021-09-21 Dentsply Ih Ab Motorized irrigation system with improved flow control
AU2017327678B2 (en) * 2016-09-16 2022-03-31 Dentsply Ih Ab Motorized irrigation system with improved flow control
US20180078700A1 (en) * 2016-09-16 2018-03-22 Dentsply Ih Ab Motorized irrigation system with improved flow control
US11672695B2 (en) 2018-03-22 2023-06-13 Artivion, Inc. Central nervous system localized hypothermia apparatus and methods
US11872368B2 (en) 2018-04-10 2024-01-16 Tandem Diabetes Care, Inc. System and method for inductively charging a medical device
US11076904B2 (en) * 2018-12-20 2021-08-03 Avent, Inc. Flow rate control for a cooled medical probe assembly
US20220015814A1 (en) * 2018-12-20 2022-01-20 Avent, Inc. Flow rate control for a cooled medical probe assembly
US11865541B2 (en) 2020-06-12 2024-01-09 Biofluidica, Inc. Dual-depth thermoplastic microfluidic device and related systems and methods
CN112524493A (en) * 2020-12-29 2021-03-19 广东石油化工学院 Device for transmitting control signal by using pipeline fluid
CN112915311A (en) * 2021-02-09 2021-06-08 苏州原位芯片科技有限责任公司 Negative feedback system control method, micropump and medical pump system

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AR040448A1 (en) 2005-04-06
US20080255502A1 (en) 2008-10-16
US8226597B2 (en) 2012-07-24
MXPA04012657A (en) 2005-03-23
US20080243058A1 (en) 2008-10-02
US8231566B2 (en) 2012-07-31
CN100548399C (en) 2009-10-14
TWI238069B (en) 2005-08-21
EP1515762A1 (en) 2005-03-23
US7879025B2 (en) 2011-02-01
TW200400839A (en) 2004-01-16
KR20050014869A (en) 2005-02-07
AU2003237402A1 (en) 2004-01-06
US20080243057A1 (en) 2008-10-02
US8672876B2 (en) 2014-03-18
CN1662269A (en) 2005-08-31
US20060142692A1 (en) 2006-06-29

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