CA2150258A1

CA2150258A1 - Automated drug infusion system

Info

Publication number: CA2150258A1
Application number: CA002150258A
Authority: CA
Inventors: Noel L. Johnson; Terry Jyh-Yi Huang; Robert R. Burnside
Original assignee: Abbott Laboratories
Current assignee: Abbott Laboratories
Priority date: 1992-11-25
Filing date: 1993-11-15
Publication date: 1994-06-09
Also published as: AU5606394A; US5547470A; WO1994012235A1; US5378231A

Abstract

The present invention relates to a control system for use with an automated intravenous drug and fluid infusion system having plulal pumping channels (4, 6, 8 10) that operate independently for intravenously infusing drugs and fluid. The pumping channels (4, 6, 8, 10) are controlled by a microprocessor-based host controller (2) that nitors each of the channels concurrently. In an exemplary embodiment, the system functions include preventing priming of a channel unless verification is provided that the channel is not connected to a patient and initiating the priming of each of the pumping channels independently.

Description

W O 94/l2235 215 0 2 5 ~ PCTrUS93/11033 AUTOMATED DRUG INFUSION SYSTEM

Bac~no~d of the Invention Field of the Invention:

The present invention generally relates to systems for delivering drugs and fluids to patients intravenously. More particularly, the present invention relates to a control system for an automated intravenous drug and fluid infusion system.

State of the Art:

It is well known to use volumetric infusion pumping systems for delivering drugs to patients intravenously. Infusion pumping systems of conventional design have several significant drawbacks that limit their effectiveness. For example, manual entry via keys and knobs is required whenever a drug supply container is connected or replaced in the pumping system. Further, conventional pumping systems require manual identification of drugs and manual priming of pumping channels.

The foregoing manual procedures are time consuming, labor-intensive and susceptible to error. Because there is no procedure for identifying and approving use of a drug in an infusion pumping system, successive use of different drugs in the same delivery line can occur, resulting in drug contamination. Further, the lack of drug identification can result in the mixing of incompatible drugs from plural drug channels.

Summar~ of the Invention The present invention relates to a control system for use with an automated intravenous drug and fluid infusion system having plural pumping channels that operate independently. Each pumping channel is independently controlled by a single microprocessor-based central processing unit (CPU). A host controller monitors all of the channels 2 1 ~ 0 2 5 8 PCT/US93/11033 , concurrently. In an exemplary ~ 'o'i --t, the syotem further includeo meano for positively identifying the particular drug that io to be pumped through a channel; means for preventing priming of a channel unleso verification is provided that the channel is not connected to a patient; and meano for independently priming each of the pumping channels.

The preoent invention provides easy to use methodo and systems which i ~ove patient care by automating control during all phases of drug and fluid delivery. The system provides pooitive identification of drugo prior to their a~ inistration via the various pumping channels, and provides autopriming of the channels. Dosing and delivery (i.e., by bolue, continuouo infuoion, or pharmacokinetic model-baoed infuoion) can be entered in u~er-selectable units which are internally converted to oyotem unito (ml/hr.).

The control syotem can also recognize incompatible drug combinationo, and suboequently handle the incompatibility or alert the de~ice user via an appropriate warning. Automatic dose limit checking, automatic data storage (e.g., patient record, user data and infusion data), and automatic detection and signaling of error conditions represent additional features of the control oystem.

Brief Deocription of the Drawinqs The preoent invention can be further understood with reference to the following description and the appended drawingo, wherein like elemento are provided with the same reference numerals. In the drawings:

Figure 1 is an exemplary automated drug infuoion (ADI) pumping syotem of the type that dispenses drugo and fluids to a patient intravenously from one or more drug and fluid supply containers;

Figure 2 io a block diagram of a control system for the Figure 1 pumping syctem;

Figures 3a and 3b illuotrate an exemplary bar code reader for a pumping channel of the Figure 2 syotem;

Figure 4 is a diagram dioplaying syotem and channel _ -nication between the user, the host controller and the independent pumping channelo of the Figure 2 syotem.

WO 94112235 1 S02s8 PCTIUS93/11033-Detailed De~cri~tion of the Preferred '~ t~

Figure 1 shows an ADI pumping ~ystem for dispensing drugs and fluids for a patient intravenously from one or more drug and fluid supply containers. The Figure 1 apparatus includes three substantially equal drug delivery channels 4, 6 and 8, and a fluid delivery channel 10.
Drug delivery parameters are entered and displayed via a touch screen 14. Fluid parameters are entered via a key pad 15. A base enclosure 50 encloses a host controller 2 for driving the overall sy~tem. A key lock 52 is disposed on a side of a pumping channel enclosure 54 and engages a security system. Detailed aspects of an exemplary drug identification and security system which can be used with the Figure 1 apparatus are set forth in c~ -n]y assigned U.S. application Serial No. 07/811,516, entitled ~Drug Channel Identification And Security System For Infusion And Pumping Systems" and filed December 20, 1991, the contents of which are hereby incorporated by reference.

Figure 2 show6 a general hardware block diagram of an automated drug and fluid infusion control system for intravenously infusing drugs and fluid to a patient via the Figure 1 pumping ~ystem. The Figure 2 system includes three general _~ ~r^nts: a host controller 2; drug channels 4, 6 and 8; and a fluid channel 10.

The Figure 2 system represents a modular, multi-channel infusion device with each drug channel holding a captive drug vial exclusively compatible with the sy~tem and with a drug admini~tration ~et. A
ma~ter-slave control approach is used, with the host controller 2 overseeing operation of the four independent pump channel modules:
three identical channels for the delivery of drug (e.g., anesthetic and cardiovascular agents), and one channel for fluid delivery.

For purposes of the following discussion, the term "drug channel"
refers to an independent path through which drug is dispensed to a patient from at least one drug supply container, or vial 32. In systems according to the present invention, each drug channel includes a cas~ette pumping device 13. Access to a drug pumping cassette 13 within a drug channel is provided by lifting a protective hood on top of the pumping system. When not in use, the hood or hoods may be locked to ~r~vent removal of the drugs.

Pump outlets in each independent drug channel may be connected to a manifold or connected directly to the patient. The preferred manifold contains four one-way check valves which connect all input lines to an W O 94/12235 PCTAJs93/11033 2~so2s8 outlet line through which drugs and fluid are dispensed to a patient intravenously, for example, a manifold such as described in commonly assigned U.S. Application Serial No. 07/734,828j entitled "Multi-Valve Manifold For Drug Infusion Systemsn, filed July 24, 1991.

A "fluid channel" refers to a path through which a fluid ~e.g., flushing fluid) is dispensed via the manifold. The Figure 2 fluid channel 10 can carry fluid such as a patient hydration solution. The fluid channel 10 includes a fluid supply container 33 which is compatible with a conven~ional drop sensor 30. The drop sen~or is connected to fluid conduit 11 that passes through a volumetric fluid channel pump. The fluid channel 10 also connects to the manifold via a one-way check valve.

The host controller 2 iB a single microprocessor-based computer which responds to user -~ -n~ directs intravenous drug and fluid deliveries, automatically recognizes drug identities, stores and selectively activates a pharmacokinetic (PK) model useful in drug delivery to the patient, handles physical incompatibilities among drugs, and provides automatic record keeping. The host controller 2 includes a microprocessor 16 which monitors and controls the independent pumping channels concurrently. The host controller 2 includes a system user interface which enables the user to identify the drug installed in each drug channel, select infusion modes, set infusion rates, identify drug incompabilities, prevent priming of a drug channel unless verification is provided that the channel is not connected to a patient, and related function~. Further, the host controller 2 causes automatic priming of each pumping channel independently.

The automatic priming removes air from each of the pump cassettes 13 and associated tubing independently. A discussion of the autoprime feature is provided in~~ ~ ly assigned U.S. patent application Serial No. 07/811,195, entitled "Automated Drug Infusion System With Autopriming" filed De- ~r 20, 1991. Because an understAn~ing of the auto-prime feature of the system described herein may be useful for a better understAnding of the present invention, the above-noted U.S.
patent application is herein incorporated by reference.

The Figure 2 system includes means for identifying the particular drug that is to be pumped through a drug channel. A modular bar code reading system 12 identifies the drug contained in a drug vial 32 installed in a drug channel of the system.

W 0 94/12235 21 S25; ~ PCT/US93/11033 The drugs normally are in liquid form in a drug container which is secured mechanically to a drug channel. A bar code which includes the drug name is included on a drug label. A bar code reader 17 is held manually as shown in Figure 3a, or can be located internally within each drug channel pump. When the bar code reader 17 i8 placed in a vicinity of the drug container, the bar code reader electronically sense~ the bar code. Further, the pumping system can use a unique arrangement of electromagnetic Hall ~ensors and magnetic strips in each drug channel to dete ine which drug channel is currently being read 80 that the reading of the drug supply container can be tied to the a~pro~Liate drug channel.

For example, in Figure 3a, Hall senoorC 15 on the bar code reader 17 detect the presence of magnetic strips 21 placed on a receptacle 19 of a drug channel. The bar code reader must be placed in a vicinity of the receptacle 19 to read a bar code on the label of a drug vial secured in the drug channel. Figure 3b ~hows an alternate configuration of a receptacle 23 which completely surrounds an end of a bar code reader 17. In this ~o~i -nt, Hall sensors 15 are replaced by a magnetic strip around a perimeter of the bar code reader. The receptacle includes Hall sensors 25 mounted thereon to detect the magnetic strip located about the perimeter of the bar code reader 17.

The Figure 2 host controller 2 operates displays 18 and peripheral~
(e.g., floppy disk drive 20 for disks 34, system bu~ interface 22 for bus 36, parallel printer interface 24 for printer 38, graphics display adapter 40 for display 18 and input/output (I/0) card 44). The host controller 2 also controls an A/D converter, a key lock switch, optional VGA compatible graphics, audio output circuitry, a timer circuit, non-volatile memory, battery backed ~tatic RAM memory for storage of non-volatile data (e.g., drug information stored in a drug table) and dynamic RAM. Power supply 42 is provided for the Figure 2 system.

The host controller 2 can set the audio volume of an audio output signal to be one of a plurality of selected volume levels. In a preferred . ~o~i --t, eight separate volume~ are provided. However, the number of selected volume levels can be greater or lesser than the number of volume levels selected for the preferred embodi --t. The audio output signal is u~ed to provide warnings or alarms to the user for when a failure, malfunction, or other alarm condition occurs within the Figure 2 system.

W O 94/1~5 PCT~US93/11033 O~s'~

The host controller 2 sends c -nds to an independent controller 9 (i.e., CPU) for each of the drug chann~ls (4,6,8) and fluid channel lO
shown in Figure 4. For example, these - -n~R include ~ignals to stop pumping, set rate or dose, prime a drug channel, change pumping rate, read dose, initiate a backprime, start a pumping operation, perform a fluid prime, change fluid pumping rate, and read a dose from the fluid channel. In addition, the host controller 2 receives responses and cases from each of the pumps.

The independent controller 9 for each drug channel controller controls and monitors pumping from drug vial~, provides automatic priming of drug sets in response to host controller 2 c~- -n~, and cl nicates statu~, alarm and error conditions within a drug channel to the host controller 2. The independent controller for a fluid channel controls and monitors pumping from fluid container~, provides automatic priming of fluid lines in response to host controller 2 c~ -nd~, and c~ nicate~ fluid line status, alarm and error conditions to the ho~t controller 2.

The three drug channel modules are based on the known LifeCare 5000, and the fluid pump module is based on the known LifeCare 175, both available from Abbott Laboratories, Inc. The independent controller~
of the drug and fluid channels are independent microprocessors which c~ nicate to the host controller 2 through a c~ -nication link.
Because the drug and fluid channel modules are, for the most part, known modules which do not themselves constitute a portion of the present invention, only features of these modules necessary for understAn~ing the present invention will be provided.

A user interface provides a connection between various pumping channel controller~ (Figures l and 2) and the user. This interface include~ a user acces~ible panel which is divided into four regions: three drug channel regions, each directly beneath one of the three drug channel mech~ni~ ~, and one fluid channel region directly beneath the fluid channel. The user can access all function~ of the Figure 2 system via the interface at any time after power-up, with the exception of ~elf-diagnostics, system ~ ini~trator function~, and floppy drive use.

In the Figure 2 ~ t, a touch screen 14 represents a module whichis accessible to the user and controlled by the host controller 2. A
key pad included on a host controller interface panel includes 16 front panel buttons in a preferred embo~i ~rt of the present -invention. The panel can accommodate additional buttons if they are needed in WO 94/12235 21 S2,~8 PCr/US93/11033 alternate embo~ t~ of the present invention, including several hidden buttons. Both an identity of a button being depressed and it~
state are read by the host controller 2.

The buttons which control drug delivery to a patient remain visible on the interface panel during the entire time delivery is occurring or is possible on that drug channel. The user is therefore not required to exit a current function to start or stop drug delivery. The drug name, current delivery rate, dose or a setpoint of the PK model, and a pumping activity indicator are displayed for each drug channel on the interface panel.

The portion of the user interface located beneath the fluid channel mechanism includes a five digit display to identify delivery rate or total value delivered. LEDs are also included on the u~er interface panel to identify a power-on condition and to indicate when the system is running on battery power.

The host controller 2 provide~ channel set up function~ for each of the drug channels 4, 6, 8 and fluid channel 10 shown in Figure 2. This includes automatic identification and channel a~ociation of drug6 placed in each drug channel and overseeing automatic priming of the drug and fluid channels. In addition, the host controller 2 provide~
drug and fluid delivery functions, system maintenance functions, data storage functions and handling of exceptional cases ~e.g., malfunction~
and alarm indications to the user).

The drug identification feature iB implemented during a drug channel set upj after the host 2 is notified by an independent controller 9 that a drug channel door has been closed with a drug cassette in place.
At that time, the host controller 2 prompts the user to scan a bar code included on a drug vial label. For the host controller 2 to accept the scan as valid, the bar coded label must be accessible to the bar code reader. The bar code reader r~ ~i n~ active as long as a drug channel door has been closed with a cas~ette in place and the a~sociated bar code label has not yet been successfully scanned.

AB described previously, two sensors provided in each channel indicate the presence or absence of the bar code reader directly in front of that channel. The drug vial to be scanned must be properly positioned in a drug channel to be identified by the bar code reader, otherwise its label will not be recognized by the system.

W O 94/ ~ 35 PCTrus93/11033 ' S'0'258 After a drug has been loaded into a drug channel and a valid bar code has been read and the drug name haff been recognized, the host controller 2 displays the name of the drug on a host display position below the drug channel receiving the drug vial. Once the bar code reader identifies the drug contained in a drug vial installed in a drug channel, the host controller 2 prompts the user to enter drug delivery information associated with that drug. The host controller 2 will not permit a drug channel to prime or pump any drug until the drug vial loaded into the channel has been successfully identified using the bar code reader.

A significant delivery function of the present invention is the abilityto provide drug specific functions. For example, the host controller 2 allows the user to pick from allowed unit conver~ion sets specified for a particular drug being used. Unit conversion sets available for each drug are retained in the drug table of the host oontroller 2 memory. Drug delivery quantities in weight based units require entry of patient weight.

More particularly, after drug identification via the bar code reader, the host controller 2 displays all delivery control quantitie~ (i.e., rate, dose and plasma level) using default units specified by a unit conversion set in the host controller's drug table for that drug, or, if preferred by the user, the units that were used during the most recent delivery of that drug. If other unit conver~ion sets are permitted for that drug, the host controller 2 permits the user to select one. Afterwards, all quantitie~ are displayed using the new unit~ for rate, dose and plasma level specified by the new unit conver~ion set.

As mentioned above, one of the primary function~ of the host controller2 is to oversee drug and fluid delivery. With regard to drug delivery, the host controller 2 is designed to control infusion rate and bolus dose delivery or PK model-based drug delivery. The ho~t controller 2 permits either bolu~ delivery or infusion delivery, but when both a bolus delivery and an infusion delivery are requested simultaneously, the bolus delivery takes priority, causing delay of the infusion delivery until the bolus has been completed.

For a bolus delivery, a bolus doce in units selected by the user mu~t be input by the user before the start of delivery. The host controller 2 will only permit a bolu~ delivery to occur for drugs which have been identified in a drug table of the host controller's memory as being deliverable by bolus. To prevent accidental delivery, the user must confirm the request for a bolus delivery prior to starting delivery.
In a preferred embodiment, the user can also select desired duration for bolus delivery ranging from default (i.e., the shortest time over which the drug can be delivered) to durations which are multiples of the default duration).

A bolus may be paused during delivery, after which the bolus may be resumed ~i.e., causing the ~ -ining dose to be delivered) or the bolus may be stopped, cancelling delivery of the ,~ -ining dose. No confirmation i8 required to resume a bolus once paused, and pausing does not affect the status of simultaneously delivered infusion delivery on the same channel.

Infusion delivery is only permitted for drugR which have been defined in the drug table as being deliverable by infusion. Continuous infusion requires that the user input a desired infusion rate and infusion units before the start of infusion delivery. A default value of infusion units is provided by host controller 2. The infusion rate is, in an exemplary embodiment, equivalent to a range of O.l ml/hr to 1200 ml/hr.

A PK model is maintained in the host controller's memory for all drugs that are listed in the drug table as having PR models. When delivery of these drugs is initiated, the host controller 2 starts a PK model to continuously predict the theoretical plasma level of the drug being delivered. The selected PK model allow~ the user to query the predicted plasma level of the drug in a patient at any time during its delivery. Again, PK model-based delivery is only permitted for drugs which have been 80 defined in the drug table of the host controller 2.
The system can provide the user with predicted (theoretical) plasma levels (i.e., level of drug in patient bloodstream) when delivering drugs by bolus or continuous infusion because a background calculation of the theoretical plasma level is continuously updated.

Before initiating a PK model-based delivery, the user must input a plasma level set point in user selectable units. The host controller 2 will not accept a plasma level set point greater than the maximum plasma level defined in the drug table for that drug. Further, PK
delivery cannot be initiated until certain patient parameters, such as weight, have been confirmed by the user. Upon initiation of a PK
delivery, the host controller 2 displays setpoint plasma level in user selected unitR, the predicted (theoretical) plasma level in the same W O 94/ ~ 35 PCTrUS93/11033-2l5o258 units, and the infusion rate in default units throughout the entire PK
model-based delivery.

In the fluid channel 10, only continuous infusion is permitted. The user must enter a delivery rate (e.g., between l and 1200 ml/hr) before fluid infusion can be initiated. In an exemplary ~ 'o~ t, only ml and ml/hr are used to define fluid rate and cumulative dose units.

A key feature of the present invention is its ability to handle incompatibility between drugs ~ ini~tered to a patient via the Figure 2 system. For this purpose, the host controller 2 detects and inform~
the user of possible physical incompatibilities between drugs identified by the bar code reader. The host controller 2 allows the user to decide whether to allow the system to automatically handle incompatible drug pairs involving bolus delivery. If the user decide~
to let the system automatically handle the incompatibility, the host controller 2 provides a visible indication on those channels that an incompatibility exists and that it will be automatically handled.

On channels where compatibility handling is active, bolus deliveries are preceded by and followed by a flush delivery from the fluid channel. Once a flush delivery for an incompatible bolus is completed, the fluid channel reverts to its previous delivery rate. The volume of each flush delivery is added to the total fluid delivered during the current patient case and stored in memory of the host controller 2.

The host controller can be designed to handle incompatibilities in all infusion mode combinations. In the preferred embo~ , the host controller 2 does not provide special handling for infusions, PK
deliveries, or for three inc -tible drugs loaded into the system at the same time, on channels where compatibility handling is active.
Rather, the host controller 2 informs the user upon identification of incompatible drug conditions. Further, a visual indication of any currently incompatible drugs is provided to the user.

For each drug loaded and identified on the Figure 2 system, the user can view the current total amount of drug delivered from the start of delivery to a particular patient. This information is stored in the host memory and is continuously updated throughout the delivery. For each drug loaded and identified, the user can specify a maximum dose limit for the duration of delivery to the patient. Once reached, the user is informed, but pumping continues. The user dose limit is reset and disabled when the patient case ends.

W 0 94/12235 21 ~0258 PCT~US93/11033 The host controller 2 also include6 a global 6top which deactivates all 3 drug channel6 at once. Each channel mu6t then be individually re6tarted to resume pumping.

Similarly, fluid specific functions are provided for the fluid channel 10. More particularly, the user can view the current total volume of fluid delivered to a patient from the beginning of the patient case.
Further, the user can enter a -Yi volume limit of fluid for each patient case. Once reached, the user is informed and fluid delivery is discontinued. The user volume limit is reset and disabled when the patient case ends.

The Figure 2 host controller 2 also provide6 a plurality of 6ystem maintenance functions. These functions include a start up/shut down function, di6k archiving function, configuration features, installation/security features, and system update.

The start up/shut down functions prev~nt drug and fluid delivery to a patient prior to user instruction to the host controller 2. The host controller 2 allows the user to end a current patient case only when no channel is pumping. Upon ending the patient case, the host controller 2 displays total volumes delivered and used for priming the ~t ini~tration get for each drug used, as well as total volume of fluid delivered and used for priming. These volumes are expressed in display units used at the time the patient case ended.

The disk archiving function of the host controller 2 stores event history and patient case information to floppy disk for later use and analysis. Configuration functions of the host controller 2 provide a means for the current date and time to be set.

At the user'6 option, access to certain functions of the host controller 2 is restricted and requires the use of a password. Once the password is ~ucce6sfully entered, the host controller 2 can be controlled to access an exception conditions log, an event history, user information, patient case information, and installation record/drug usage. Further, at the user'6 option, entry of this password can be required before information stored in the system can be transferred to the floppy disk. In addition, entry of the correct password can be used to control entry of information into the host controller's memory (e.g., hospital name, drug table updates and names of u6ers allowed access to the sy6tem).

W O 94/ ~ 35 PCTrus93/11033 2lso258 The password cannot be chAnged unless accesQ to the system ha~ been obtained, nor can the password be viewed unless access to the system ha~ been obtained following accurate entry of the current password.
Use of the password can thus be used to control access to a variety of feature~ of the host controller 2.

As mentioned above, the present invention can provide data storage of event history, an exception conditions log, u~er information, patient case information, in~tallation record/drug usage and drug table~.
Event history data is stored by the host controller 2 as a chronological record of system cases associated with the Figure 2 sy~tem alarms, malfunctions, and user interaction with the system. ~he event hi~tory data is stored in the non-volatile host controller's memory, and can be viewed by the user.

In an exemplary embo~ t, the ho~t controller 2 can ~tore all ca~e~
that occur over a period of 7 days of continuous u~e. Once the case buffer is filled, old ca~es are discarded as new cases occur. The host controller 2 permits the user to disable and enable event history recording, and when disabled no subsequent ca~eR are stored in the event hi~tory portion of the host controller's memory.

Exception conditions are stored by the host controller 2 as a chronological record of at least the last 30 exception conditions (i.e., malfunctions and alarms) applicable to the entire Figure 2 system. Again, thi~ log is stored in a non-volatile area of host controller's memory. Pumping channel exceptions are not stored in the individual pumps, but are stored as data in this portion of host controller's memory. Exception data is recorded automatically and cannot be disabled or erased by the u~er.

The ho~t controller 2 al~o stores user information. This information includes, for example, up to 100 alphA -ric user IDs in a non-volatile area of host controller's memory.

Patient case data can, in an exemplary embo~ t, be retained on the last 50 patient cases. The host controller 2 allows the user to optionally store a patient ID a~ well a~ other information on age, ~ex, and weight. The patient weight can be input and displayed in pounds or kilograms.

For each patient ca~e, the host controller 2 stores the u~er ID of the uHer who ended the patient ca~e, the total number of user~ who W O 94/12235 PCTrUS93/11033 2t~0~s8 identified themselves to the system during the patient case, the time the patient case started, and the duration of the patient case. The host controller 2 al~o records the number of drugs delivered during the patient case, the total volume delivered and total volume used in priming for each drug used during the patient case, as well as the total volume of fluid delivered and total volume used in priming. This information is expressed in display units currently being used at the time the patient case ended.

Installation record/drug usage data is retained by the host controller 2 and includes information regarding the installer's name, the site name, installation date and information pertaining to specific hardware configuration of the Figure 2 system.

Drug table data is also stored by the host controller 2. The drug table include~ information (e.g., drug incompatibilities, suitability for bolus infusion delivery or PK delivery, PK model-based input parameters and -Yi m allowable infusion rates, bolus doses, and theoretical plasma levels) for each drug as described previously.

Another key feature of the present invention is its ability to handle exception condition~. More particularly, when a malfunction, audible alarm or audible warning occur~, audio signal is emitted by the host controller 2 to alert the u~er. This audio signal is only discontinued when the user has acknowledged the condition, but may be temporarily stopped using a silence alarm button on the host controller interface panel. When a non-audible alarm or non-audible warning occur~, a discrete audio signal is optically generated to alert the user.

The host controller 2 detects malfunctions in the Figure 2 system.
Malfunctions which are identified by the host controller 2 and c~ nicated to the user include signals indicating that a fluid or drug channel is unavailable due to an internal malfunction, indication that the system is unavailable due to a malfunction, and indications that the disk drive or other peripheral components are unavailable due to a malfunction.

The system can be configured to require presence of a drop detector in the fluid channel. When 80 configured, the host controller 2 require~
the user to discontinue fluid channel operation when an alarm indicating the absence of a drop detector occurs. The fluid channel cannot be restarted until the exception condition regarding absence of the drop detector is rectified.

W O 94/12235 PCTrUS93/11033 2ls~258 Alarms associated with the fluid delivery channel 10 include, for example, indications that the fluid channel autoprime mechani~m has failed, that there is air in the fluid channel line, that the fluid channel door has been opened while pumping or that the fluid channel bag is empty. When fluid iB unavailable, the host controller 2 allow~
the user to stop the fluid channel 10 and enter a new pumping rate, but the fluid channel 10 cannot be restarted until the exception condition is rectified. Alarms are also generated when there is a proximal occlusion or distal occlusion in the fluid channel pump, when there is a pressure error in the fluid channel 10, when the fluid channel volume limit is reached. In a preferred ~ ~o~i ~rt, the foregoing alarms are the i ni alarm conditions provided. Those skilled in the art will recognize that any number of alarms based on detection of any desired condition can be provided.

In a preferred embo~ t, alarms associated with the drug channels 4, 6, 8 are, at a i n i , provided to the user when there is proximal or distal air detection in the drug channel cassette 13, when a channel door has been opened while pumping, when there is a proximal or distal occlusion in the cassette, when distal pressure is out of range, or when drug is unavailable. Non-audible alarms generated by host controller 2 include when AC power is not available or when the battery bec~ -8 discharged, failure to recognize a bar code, failure to associate a bar code with a channel, or alarms associated with floppy disk operation.

In a preferred embodi --t, audible warnings (i.e., potential alarm condition) include, at a i n i , when the battery is low or when a drug container is near empty. Non-audible warnings include detection of excess air in an air trap chamber of a pumping cassette, 1088 of AC
power or potential drug inc~ -hilities.

Drug and fluid channel status conditions are also continuously provided from the pumping channels to the host controller 2 for display. Status condition~ which are displayed to the u~er via the host controller interface panel include, channel unavailable status, inactive statu~, autopriming status, backpriming status, testing cassette status, cassette test failure status, prime needed status, backprime needed status, prime verification needed statu~, infusion on hold status, bolus on hold status.

System status conditions which can be displayed via the host controller interface panel include: battery low status, security covers locked WO 941L~235 21 S 0 2 ~ PCT/US93/11033 status, fluid channel unavailable status, drop detector missing status, volume limit reached status, disk drive unavailable status, patient parameters needed status, and user ID needed status.

As illustrated by Figure 4, user interaction with the Figure 2 system is via a user interface 3 in the host controller 2. C- nication of c- 9n~ data, exception conditions, status and other information between the host controller 2 and drug and fluid channels is via the aforementioned serial ~_ nication link, capable of two-way communication. Communication is, for example, via packets limited to 30 bytes to ensure real time operation. Typical communications between the host controller 2 and pumping channels is via a r -nd-acknowledgement loop. The host controller 2 (master) sends a c~ ~nd packet to one of the four pumping channel controllers 9 (slave), or vice versa. Tne targeted channel ~end~ back an acknowledgement indicating receipt and initiation of appropriate action in response to the command.

Master-slave polling is used to detect synchronous c~ nications between the host controller 2 and pumping channels 4, 6, 8 and 10.
These synchronous c~ nications include, for example, the aforementioned alarms and door open/door closed conditions. When, alarm conditions are sent from a pumping channel 4, 6, 8 and 10 to the host controller 2, the pumping channel awaits acknowledgement from the host controller 2. If an event is not acknowledged within a set time frame, the event is retransmitted until acknowledgement is received.
After acknowledging the pump channel cc -nication, the ho~t controller 2 can either send a reset command to the pump or report failure to the user. For multi-event conditions, a pumping channel module will queue cases until all are acknowledged.

When multiple c~ -nd packets are received or sent by the host controller 2, either the entire c~ -nd packet is completed or the entire command packet is aborted. Thu~, if an alarm condition occurs during execution of a multi c~ -nd packet, the partial c~ -nd packet is not processed. Rather, the entire packet must be resent and executed in its entirety.

Where an illegal c~ ~nd is attempted, the command is ignored. An illegal ~ -nd represents a c~ -nd that cannot be processed at the time it is received. For example, when a drug channel 4, 6 and 8 is an unprimed state, a start command which is received cannot be executed.

WO 94/12235 ~CT/US93/11033 21~02~ 16 A more detailed discussion will now be provided of the drug channels 4,6 and 8. Each drug channel 4, 6 and 8 includes a pump which is preset at a position having an outlet valve closed, and an inlet valve open.
A closed door switch i8 included in each drug pump to indicate when a drug channel door is closed with a cassette in place. An open door switch indicates that the drug channel door has been opened.

Pumping is accomplished in each drug channel via a pumping cassette which includes one or two proximal (inlet) lines and one distal (outlet) line. The pump includes a mechanical reciprocating plunger -ch~nin and a pumping cassette through which the drugs are pumped.
The pumping cassette has a primary inlet port and a pumped-liquid outlet port. The primary inlet port is connected to a piercing pin for receiving drug from a vial. However, alternative drug containers and connection methods can be used. The cassette also includes a secondary inlet port which 1. -in~ normally closed. However, if desired, the secondary inlet port can receive a second drug, or drug diluent, for mixing with drug which has been introduced to the cassette via the primary inlet port.

A principal function of the independent controller 9 in each drug channel is to control drug delivery, priming of the drug delivery line, cr nication with the host controller 2, error detection and error reporting within the drug channel. The principal activity of the drug channel i8 drug delivery, whereby liquid is moved from one of the cassette inlet lines to the outlet line. The inlet lines, referred to herein as primary and second~ry inlets, are typically configured with the primary line connected to a drug vial, and the secondary line disconnected. An exemplary delivery range is from .1 ml/hr to 1200 ml/hr.

For each pumping cassette, the drug channel controller responds to userc -n~s to control bi-directional flow. Bi-directional flow control is critical for autopriming. During autopriming, the host controller 2 instructs operation of the valve actuators and plungers in each drug channel to displace air from the drug cassette. Further, the autopriming sequence can be used for priming the output line to the patient.

Each drug channel receive~ c~ -nds directly from the host controller 2 via the serial c~ lnication interface at an exemplary data rate of 1200 baud. These Cl -n~ include the aforementioned cr nications to set rate, start pumping and so forth. Each independent controller 9 WO 94/12235 1S02S~ PCT/US93/11033 detect~ anomalies within its own drug channel pumping line. Error conditions and significant cases are c~ nicated by each channel controller to the host controller 2.

Three different priming operations are required for the drug channel:
the drug channel can fill, with drug, a cassette which is full of air distal to the air trap chamber (i.e., completely empty cassettes,-cassettes with air in the pumping bowl, and cassettes with air in the distal tubing); the drug channel can remove air introduced into the cassette air trap without moving it to the outlet line; and the drug channel can remove air trapped between the secondary inlet and an optional secondary reservoir. The drug channel detects errors and reporting is performed by the drug channel to the host controller 2 with respect to four classes of error~: electronic, mechanical, cassette and c~ nication.

Electronic integrity verification concerns the microprocessor memory, A/D line~ and other microprocessor board and sensory apparatus.
Mechanical integrity verification concerns verifying the mechanical pumping system is moving in accordance with c~ -nded operation via the use of position detection feedback on three stepper motors included in each drug channel. Cassette integrity verification ensure~ that a cassette introduced to a drug channel i8 capable of withstanding pre~sures associated with pumping without leaking and is not occluded.
Cc n ication error detection is nece~sary to verify that transmitted data is accurate in accordance with the serial c lnication protocol.
All failures are transmitted by the drug channel to the host controller 2, and the drug channel will confirm that the host controller 2 i8 aware when an alarm condition exi~ts.

More particularly, electronic integrity verification is used to verify electronic and software integrity. For example, on power-up, the drug channel performs a RAM test, a ROM test, an A/D converter test and a watchdog test. The drug channel verifies serial c~ nication integrity by the on-going existence of incoming message packets. The drug channel verifie~ integrity of the air sensor by ensuring an air signal is seen whenever the door is open.

Mechanical integrity verification to ensure safety, involves verifying an ability of the pump channel mechanism and cassette to pump accurately. These te~ts are performed before pumping, and if any test fails, the drug channel i~ not permitted to pump. Motor position check and re-synchronization tasks (if necessary) are performed prior to W O 94/ ~ 35 - PCT~US93/11033 '~15~258 pumping ~e.g., when the system i8 activated), and no maximum time requirements are associated with these tasks.

Another function of each drug channel (4,6,8) i8 to perform a cassette integrity test to check for static occlusion and valve leaks when a cassette door is closed with a cassette in place. Occlusion detection is performed via the proximal and distal pressure sensors (i.e., pressure threshold is exceeded on proximal or distal side)~ after which an occlusion alarm is reported by the affected drug channel to the host controller 2.

Leak tests are performed automatically whenever the cassette door i8 closed with a cas~ette in place. All of the~e tests are performed by monitoring pres~ure inside the cassette and are, for example, u~ed to indicate the need for backpriming the cassette (automatic removal of air from the cassette done by pushing it back into the drug container) or to indicate that a bad cassette need~ to be replaced. The proximal pressure sensor self-test is used to ensure that the pressure sensor stays within a desired operating range.

A priming function of each drug channel (4,6,8) removes air from the drug delivery set. A drug delivery set includes a pumping cassette, distal tubing, and vial adapter. Priming operations perform both proximal and distal occlusion detection.

A pumping function is initiated in response to a start pumping command after all integrity tests have been implemented and passed. During pumping, mechanical motor position flags are monitored continuously by optical sensors.

The pumping function of the drug channel provides for proximal occlu~ion detection and distal occlusion detection using proximal and distal pressure sensor~, respectively. A distal air in line alarm and stop pumping signal are generated by a drug channel if an air bubble (e.g., greater than, for example, 100 ~Q) (microliter), occurs at the distal air detector. The pump will also generate a distal air in line alarm if, for example, 200 ~Q out of the last 2.0 ml of volume wa~ air.

The pumping function also includes an empty container detection when cumulative amount (e.g., 200 ~Q) of air has entered the cassette from at least one inlet line. This cumulative total is reset whenever the cassette door is opened, or a priming operation is performed.

W O 94/l2235 1S02S8 PCT~US93/11033 i9 A door open detection mode of the drug channels 4, 6, and 8 is used to trigger return of the step motors in a given drug channel to a preset position. At all times except for electronic self-tests, (i.e., pumping, priming, and so forth)~ a "door opened" alarm is generated and transmitted to the host controller 2. After the door is opened, the drug channel retains pumping parameters (i.e., rate, dose limit, delivered dose) except for pressure limit. When the door is again clo~ed, the drug channel retains all of these parameters until commanded to change by the host controller 2.

A description will now be provided of a fluid channel lO control. A
fluid pump within a fluid channel includes a plunger/inlet valve/outlet valve assemb1y and a DC motor to pump fluid.

The fluid channel controller 9 communicates with the host controller 2 via the serial c~ nication interface to receive c-- -nd8 such as set rate, start and operational commands. Like the drug channels, the fluid channel lO detects anomalies in the pumping line and cnmmlnicates error conditions and significant cases to the host controller 2.

The fluid channel lO controls fluid delivery from inlet tubing to outlet tubing in an exemplary range of from l ml/hr to 1200 ml/hr.
Further, the fIuid channel lO controls priming of air filled delivery tubing automatically. Like the drug channels, the fluid channel can detect four similar classes of errors: electronic, mechanical, fluid and communication.

Because pumping is the primary function of the fluid channel lO, various parameters are accessible by-the host controller 2 to configure the fluid channel behavior during pumping cycles. These parameters include delivery rate, dose limit, drop detector, priming time limit and door closed flag. The drop detector parameter determines whether detection of an empty fluid container is required during the delivery cycle. This parameter can be selectively requested by the host controller 2. The priming time limit parameter provides fail-safe operation of the priming process. The door closed flag ensures that pumping and priming do not occur unless the delivery tubing is inserted and the pumping mechanism door latches closed. The flag is set whenever both the delivery tubing is inserted and the door latch is closed, and either a door opening or tubing removal will reset this flag.

Pumping functions of the fluid channel lO include a priming cycle and W O 94/ ~ 35 ; PCTAJS93111033 2lso258 a delivery cycle. Priming of the delivery tubing in response to a command from the host controller 2 consists of two phases: a proximal tubing filling phase and a distal tubing filling phase. During the proximal tubing filling phase, the fluid channel 10 activatee its priming mechanism and starts pumping until a distal air sensor detects continuous fluid flow. After continuous fluid flow is detected, the priming mechanism is deactivated and control advances to a distal tubing filling phase. In the distal tubing filling phase, fluid is delivered at a specified delivery rate until the specified dose limit is reached as with a normal delivery cycle. The only difference is that when an air-in-line condition is detected during the distal tubing filling phase, the priming cycle returns to the proximal tubing filling phase in~tead of terminating the priming process.

Priming is discontinued when a specified dose limit i8 reached during the distal tube filling phase, upon receipt of a stop c~ -nd from the host controller 2, upon expiration of a priming time limit, upon detection of an empty container by a drop detector, or by an alarm in response to error detection. During the delivery cycle, the fluid channel 10 delivers fluid from its proximal tubing to its distal tubing at the specified delivery rate, until stopped by the user or the user specified dose limit i~ reached.

Error detection is similar to that of the drug channels and include~
electronic, mechanical and fluid integrity checks. An error detected by these tests results in stoppage of the pumping process and c~ nication of the error to the host controller 2.

For example, electronic integrity verification includes use of a watchdog timer to interrupt the fluid channel CPU to ensure integrity of the fluid channel CPU, critical data storage verification, and sensor range verification with regard to temperature and power supply voltage~. M~chAnical integrity verification includes monitoring of motor slippage, monitoring of plunger motor shaft encoder ~lippage, pumping rate verification and motor voltage verification. Fluid integrity verification includes air-in-line detection, empty container detection, proximal occlusion detection, distal occlusion detection and differential distal occlusion detection (i.e., when average depositive pressure buildup of distal pressure, relative to the distal pressure at pumping start time, is detected). Detection of a drop detector (if re~uired) and 1088 of the drop detector signal are also monitored.

It will be appreciated by those skilled in the art that the present W O 94/12235 21 S O ~ S 8 PCT~US93/11033 invention can be embodied in other ~pecific forms without departing from the ~pirit or e~ential characteri~tics thereof. The pre~ently diHclosed ~ are therefore considered in all reQpect~ to be illustrative and not restrictive. The scope of the invention i~
indicated by the appended claim~ rather than the foregoing de~cription, and all change~ that come within the meaning and range of equivalent~
thereof are intended to be embraced therein.

Claims

What is Claimed is:

1. A control system for use with an automated intravenous drug and fluid infusion system, said control system comprising:
plural pumping channels that operate independently for intravenously infusing drugs and fluid, each of said pumping channels having a pumping channel controller for independent delivery in multiple infusion modes; and a host controller that monitors each of the pumping channels concurrently.

2. A control system according to claim 1, further including:
a bar code system for reading a bar code from a supply container to be used in a pumping channel, said supply container holding a drug, a fluid or a combination of a drug and a fluid.

3. A control system according to claim 2, wherein said bar code system further includes:
sensors located within at least one of said pumping channels to detect a presence of the bar code reader in a vicinity of at least one pumping channel.

4. A control system according to claim 3, wherein said sensors include:
electro-magnetic sensors which are arranged in each pumping channel to detect the presence of the bar code reader, the arrangement of sensors in each channel being different to uniquely identify each channel.

5. A control system according to claim 4, wherein said sensors are Hall effect sensors.

6. A control system according to claim 5, wherein said host controller receives signals generated within each of the pumping channels to identify a drug or fluid selected for use in that channel, and to control channel priming and delivery in response to the received signals.

7. A control system according to claim 6, wherein said host controller further includes:
a touch screen for user entry of control information, including drug dose and drug delivery rate for each drug pumping channel, and fluid delivery rate for each fluid pumping channel.

8. A control system according to claim 7, wherein said host controller further includes:
a display for displaying a selected drug, drug dose and delivery rate to the user for each drug channel, and for displaying fluid delivery rate for the fluid channel.

9. A control system according to claim 8, wherein each pumping channel control responds to commands from the host controller to perform pumping channel priming and delivery, and to signal error and status conditions of each pumping channel to the host controller, such that delivery of significant air to a patient is prevented.

10. A control system for use with an automated intravenous drug and fluid infusion system, said control system comprising:
plural pumping channels that operate independently for intravenously infusing drugs and fluid, each of said pumping channels having a pumping channel controller for independent delivery of drug and/or fluid in multiple drug infusion modes;
a host controller that monitors each of the pumping channels concurrently, each of said pumping channels further including:
automatic priming means for removing gases from each pumping channel independently to prevent delivery of significant air to a patient; and means for preventing priming of a channel unless verification is provided that the channel is not connected to a patient.

11. A control system according to claim 10, wherein said preventing means further includes:
means for identifying a drug and fluid selected for use in each pumping channel.

12. A control system according to claim 11, further including:
a user touch screen for entering control information, said control information including drug dose and drug delivery rate for each drug pumping channel, and fluid delivery rate for each fluid pumping channel.

13. A control system according to claim 12, further including:
means for displaying a selected drug, drug dose and delivery rate to the user for each drug channel, and displaying fluid delivery rate for the fluid channel.

14. A control system according to claim 13, wherein each of said pumping channel controllers further includes:
means for responding to commands to perform channel priming and delivery, and for signaling error and status conditions of each pumping channel.

15. A control system according to claim 14, wherein said host controller includes:
means for determining whether drugs selected for one or more pumping channels are compatible; and means for displaying incompatible drugs to the user.

16. A control system for use with an automated intravenous drug and fluid infusion system, said control system comprising:
plural pumping channels that operate independently for intravenously infusing drugs and fluid, each of said pumping channels having a pumping channel controller for independent delivery from each channel in multiple infusion modes;
a host controller that monitors each of the pumping channels concurrently, each of said pumping channels further including:
means for identifying a particular drug that is to be pumped through a drug pumping channel.

17. A control system according to claim 16, wherein said identifying means further includes:
a bar code system for reading a bar code from a drug supply container to be used in a pumping channel.

18. A control system according to claim 17, wherein said identifying means further includes:
means for detecting a presence of a bar code reader in a vicinity of at least one pumping channel.

19. A control system according to claim 18, wherein said detecting means includes:
electro-magnetic sensors in each pumping channel to detect the presence of the bar code reader, the arrangement of sensors in each channel being different to uniquely identify each channel.

20. A control system according to claim 16, wherein said host controller further includes:
means for prompting a user to input pumping channel control parameters; and means for converting quantities designated by the user into units for processing by the host controller.

21. A control system according to claim 16, wherein said host controller and at least one pumping channel controller include:
means for controlling pharmacokinetic-based delivery of a drug; and means for displaying predicted plasma level based on the pharmacokinetic-based delivery.

22. A control system according to claim 16, further including:
means for maintaining an updated log of drug and fluid delivery, including a record of system errors which have occurred during delivery.