WO1987002590A1

WO1987002590A1 - Positive-flow, demand responsive, respiratory regulator

Info

Publication number: WO1987002590A1
Application number: PCT/US1986/002412
Authority: WO
Inventors: Douglas C. Howard; Merton L. Westcott
Original assignee: Shattuck, Leonard, L.
Priority date: 1985-11-05
Filing date: 1986-11-04
Publication date: 1987-05-07
Also published as: EP0245468A1; BR8606954A; AU6622686A; FI872902A; FI872902A0; OA08625A; KR880700676A; JPS63501547A; EP0245468A4; HUT44183A

Abstract

A positive-flow, demand responsive, respiratory regulator (5) which controls the administration of gaseous fluid(s). As the patient begins the inspiration phase of the respiration cycle, a pressure decrease at a static sensor port (11) causes a breathing pressure augmentation diaphragm (21) to move toward the static sensor port. This causes opening of a positive pressure shut-off port (18) allowing dragon-fly diaphragms (20 and 27) to move upward thus opening the fluid supply inlet port (6). The open fluid supply inlet port creates fluid communication of gaseous fluid(s) to the patient. During the expiration phase of the respiration cycle a pressure increase at the static sensor port (11) causes the breathing pressure augmentation diaphragm to close the positive pressure shut-off port (18). This causes the dragon-fly diaphragms (20 and 21) to move downward, closing the fluid supply inlet port (6). The closed fluid supply inlet port prevents fluid communication of gaseous fluid(s) to the patient. If the patient's exhalation is very weak, the positive pressure shut-off port remains open and oxygen flow to the patient is not interrupted.

Description

POSITIVE-FLOW, DEMAND RESPONSIVE, RESPIRATORY REGULATOR

BACKGROUND OF THE INVENTION

5

Field of Invention

The present invention generally relates to a respiratory regulator for administering gaseous fluid(s) to patients and, more particularly, is concerned with

T__Q positive-flow, demand responsive, respiratory regulator.

Setting for the Invention

Positive pressure respiration systems are used in inhalation therapy for individuals requiring administration τ_5 of oxygen and/or adjuvant gaseous fluids for breathing, or administration of such gaseous fluid(s) for assistance in breathing. Typical conventional respirators cycle from inspiration to expiration phases by operation of fluid amplifiers pneumatically controlled valves, snap valves,

20 magnetically influenced valves, electronic circuitry, and other regulatory mechanisms. The dynamics and multi-component nature of these respiratory systems reflect inherent problems of manufacture, cost, size restrictions, system failure, and system efficiency.

25 Positive pressure respiration systems are categorized according to the fluid administration requirements of the patients as denoted above. One such category includes positive pressure volume limited respiration systems which operate by administering a

30 predetermined volume of gaseous fluid(s) into the patient's lungs at predetermined intervals. A second category includes positive pressure flow limited respiration systems which function in response to a patient's respiratory cycle, allowing the patent to inspire a volume of gaseous fluid(s)

35 which the patient's lungs will accept. Still, a third category consists of positive flow respiration devices which continuously deliver a regulated, but constant, volume of gaseous fluid(s) the patient during inspiration as well as during expiration.

Consequently, a need exists for improvements in positive pressure respiration systems, including the flow limited type, in order to move effectively meet the therapeutic needs of patients.

Objective- αf: the Invention

Accordingly, it is an objective of the invention

10 to provide a positive-flow, demand responsive, respiratory regulator for administration of gaseous fluid(s) to a patient.

Another object of the invention is to provide a positive-flow, demand responsive, respiratory regulator ■_jc wherein an intermittent volume of gaseous fluids is actuated by pressure variations of the patient's respiratory cycle.

Still another object of the invention is to provide a positive-flow, demand responsive, respiratory regulator where the absence of sufficient positive pressure 2_Q by the patient would cause a flush flow condition, thereby providing flow of gaseous fluid(s) to the patient, and rendering the system fail safe.

Still another object of the invention is to provide a positive-flow, demand responsive, respiration 25 regulator in which the wasteful "venting" of the fluid is minimized.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification 3 and covered by the claims appended hereto.

SUMMARY OF THE INVENTION

c The present invention is a positive-flow, demand responsive, respiratory regulator which controls the administration of gaseous fluid(s) from a pressurized and regulated supply conduit through a delivery conduit and cannula to a patient. As the patient begins inspiration, pressure in a static sensor port line decreases, causing a breathing pressure augmentation diaphragm to move toward a

5 static sensor port. This causes opening of a positive pressure flow shut-off port allowing pressure above a dragon-fly diaphragm to move the diaphragm upward thus opening the fluid supply inlet port. Gaseous fluid(s) flow from the fluid supply inlet port to the fluid supply outlet

J_Q port and then into a delivery conduit and cannula to the patient. When the patient's respiration cycle switches to exhalation, pressure in the static sensor port line and the static sensor port increases. This causes the breathing pressure augmentation diaphragm to move away from the static

15 sensor port, thus closing the positive pressure flow shut-off port. Then the dragon-fly diaphragm moves downward thus shutting off gaseous fluid(s) flow.

If the patient fails to or is unable to exert pressure to the static sensor line and static sensor port

20 during the patient's respiration cycle, supply pressure through a small bleed port or diaphragm port in the dragon-fly diaphragm causes opening of the positive pressure shut-off port, allowing the dragon-fly diaphragm to move upward thus opening the fluid supply inlet port. Gaseous

25 fluid(s) flow from the fluid supply inlet port to the fluid supply outlet port and then into a delivery conduit and cannula to the patient, thus causing a flush flow condition.

30 BRIEF DESCRIPTION OF THE DRAWINGS

The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which: 35 FIG. 1 is a schematic view of a respiratory system embodying the principles of the present invention, FIG. 2 is an enlarged cross-sectional view of a positive-flow, demand responsive, respiratory regulator,

FIG. 3 is an enlarged cross-sectional view of a positive-flow, demand responsive, respiratory regulator depicting the arrangement of its component ports in response to negative pressure at the static sensor port during the inspiration phase of the respiration cycle, and

FIG. 4 is an enlarged cross-sectional view of a positive-flow, demand responsive, respiratory regulator depicting the arrangement of its component parts in response to positive pressure at the static sensor port during the expiration phase of the respiration cycle.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to Figure 1, a respiratory system embodying the principles of the present invention is shown. Repiratory fluid is supplied from a pressurized source 8, through supply conduit 9 , and flow meter 10, to a supply inlet port 6 in the housing 7 of the positive-flow, demand-responsive, respiratory regulator 5. The flow then passes to a fluid supply outlet port 14, through a delivery conduit 15, to a nasal cannula 13, and to the patient. A static sensor port line 12 is connected from a static sensor port 11 of the regulator 5, to the cannula 13.

Figure 2 is an enlarged cross-sectional view of a positive-flow, demand responsive, respiratory regulator 5 which includes a fluid supply inlet port 6 embodied in the respirator regulator housing 7, said port being in fluid communication with a pressurized source. A static sensor port 11 is embodied in the respirator regulator housing 7 and is in fluid communication with the patient by means of a static sensor port line. A fluid supply outlet port 14 is embodied in the respiratory regulator housing 7 and is in fluid communication with the patient by use of a delivery conduit. A bleed port 17 is embodied in the respiratory regulator housing 7 and is in fluid communication with surrounding ambient atmospheric pressure. The bleed port 17 serves to maintain an internal pressure equilibrium within the respiratory regulator housing 7 by allowing the escape of gaseous fluid(s) passing through a positive pressure flow shut-off port 18 from a diaphragm port 31 in a dragon-fly diaphragm 36. A breathing pressure augmentation diaphragm 21 is housed within the housing, and divides sense-side compartment 34 into a first component pressure chamber 22 and a sensor chamber 24 of the respirator regulator housing 7. The first component pressure chamber 22, in addition, has interface with the bleed port 17, and a second component pressure chamber 23 via a positive pressure flow shut-off port 18. The rest position of the diaphragm 21 is at plane 28. The sensor chamber 24 communicates with the static sensor port 11.

A flow-side compartment 35 in the housing 7, is divided into three chambers. A second ςomponent pressure chamber 23 and an intermediate chamber 26 are separated by a dragon-fly diaphragm upper leaf 20, which has a rest position at plane 29. The intermediate chamber 26 and a flow chamber 25 are separated by a dragon-fly diaphragm lower leaf 27, which has a rest position at plane 30. A control stop 32 is mounted on the breathing pressure augmentation diaphragm 21 so that, when the diaphragm 21 is displaced toward the shut-off port 18, the shut-off port 18 is closed by the control stop 32. The second component pressure chamber 23 has interface with the flow chamber through diaphragm port 31 and with the first component pressure chamber 22 via the positive pressure flow shut-off part 18. The flow chamber 25 communicates with the inlet port 6 and the outlet port 14. A flow stop 33, with diaphragm port 31 through it, is sealed to the dragon-fly diaphragm upper leaf 20 and the dragon-fly diaphragm lower leaf 27 and extends into flow chamber 25. The flow stop 33 is positioned so that, when the diaphragms that carry it are displaced toward the inlet port 6, the flow stop closes the inlet port 6 off from the flow chamber, but continues communication between the inlet port 6 and the second component pressure chamber 23.

Figure 3 is an enlarged cross-sectional view of a positive-flow, demand responsive, respiratory regulator when, during the inspiration phase of the respiration cycle, tne pressure in the static sensor line 12 and sensor chamber 24 decreases, causing the breathing pressure augmentation diaphragm 21 and control stop 32 upward to move toward the static sensor port 11. This causes opening of the positive pressure flow shut-off port 18, which in turn causes pressure above the dragon-fly diaphragm upper leaf 20 to decrease from supply pressure to atmospheric and the dragon-fly diaphragms 20 and 27 to move upward, thereby opening the fluid supply inlet port 6. The open fluid supply inlet port 6 opens fluid communication of gaseous fluid to the patient. The fluid flows from the flow chamber 25, through the fluid supply outlet port 14, through the delivery conduit 15, and is administered via the cannula 13. Figure 4 is an enlarged cross-sectional view of a positive-flow, demand responsive, respiratory regulator when during the expiration phase of the respiration cycle, the pressure in the static sensor line 12, port 11, and sensor chamber 24 increases, causing the breathing pressure augmentation diaphragm 21 and control stop 32 to move away from the static sensor port 11. This causes closing of the positive pressure flow shut-off port 18 by control stop 32, which in turn causes pressure above the dragon-fly diaphragm upper leaf 20 to increase and the dragon-fly diaphragm upper leaf 20 to move downward, thereby closing the fluid supply inlet port 6 to the flow chamber 25, but not to chamber 23. Tne pressure in the chamber 23 (supply pressure) overcomes the pressure in the flow chamber 25 (initially at supply pressure), because the exposed area of the diaphragm upper leaf 20 to chamber 23 is far greater than the exposed area of diaphragm 27 to the flow chamber 25. The closed fluid supply inlet-port 6 prevents fluid communication of gaseous fluid to the patient, but allows fluid supply to chamber 23.

Whenever, after the non-flow condition shown in Figure 4, if the patient fails to or is unable to exert sufficient pressure (atmospheric pressure plus a safety margin) to the static sensor port 11, via the patient's respiration cycle and line 12, the system automatically returns to a flow condition shown in FIG. 2. Referring to the non-flow condition in Figure 4, the diaphragm port 31 maintains the chamber 23 at supply pressure. When the combined force of the pressure (supply) in chamber 23 against the control stop and of the pressure (atmospheric) in chamber 22 is greater than the force on diaphragm caused by the pressure in chamber 24, diaphragm 21 moves toward the sensor port 11, shut-off port 18 opens, and the pressure in chamber 23 is vented through bleed port 17. This allows the dragon-fly diaphragm upper leaf 20 to move toward port 18 thus opening the fluid supply inlet port 6. Gaseous fluid(s) flows into the fluid supply inlet port 6 from the fluid supply outlet port 14 and then into a delivery conduit 15 and cannula 16 to the patient, thus causing a flush flow (fail-safe) condition.

The safety margin is essentially the pressure above atmospheric which the patient must cause in chamber 24 in order to allow the non-flow condition. It is the pressure-equivalent which is approximately equal to the force on diaphragm 21 caused by the pressure in chamber 23 on the control stop 32. Thus, the safety margin can be set by setting the effective area of the diaphragm 21 and port 18 on which the pressure in chamber 23 acts. Because the diaphragm port 31 is very fine (much finer than ports 18 or 17), very little of the medicinal fluid is actually vented. Thus, waste is minimized and safety is maximized. This relationship of ports also causes effective relational timing of the diaphragm movements. It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent is:

10

ID

20

25

30

35

Claims

1. A positive-flow, demand responsive, respiratory regulator, which controls the administration of gaseous fluiά(s) from a supply conduit into a delivery conduit and cannula to the patient, said respiratory 5 - regulator comprising:

(a) a housing,

(b) a fluid supply inlet port embodied in the housing, said inlet port being in fluid communication with a supply conduit,

10 (c) a static sensor port embodied in the housing, said static sensor port being in fluid communication with the patient by means of a static sensor port line and cannula, where fluctuations in pressure at the static sensor port, corresponding to respiratory signals,

15 causes responsive movement of a breathing pressure augmentation diaphragm, (d) a fluid supply outlet port embodied in the respiratory regulator housing, said outlet port being in fluid communication with the patient by means of a delivery

20 conduit and cannula said delivery condudit and cannula providing for the administration of gaseous fluid(s) to the patient, and (e) a bleed port embodied in the respiratory regulator housing, said bleed port being in fluid communication

25. with surrounding ambient atmospheric pressure, where the bleed port serves to maintain an internal pressure equilibrium within the interior of the respiratory regulator housing by allowing the escape of gaseous fluid(s).

30

2. A respiratory regulator as claimed in Claim 1, wherein a breathing pressure augmentation diaphragm is housed within a first compartment of the respiratory regulator housing said first compartment having interface

35 with the static sensor port, the bleed port, and a second compartment chamber.

3. A respiratory regulator as claimed in Claim 2, wherein a- dragon-fly diaphragm is housed within a second compartme-t of the respiratory regulator housing said second compartment having interface with the fluid supply inlet port^*-,.- the, fluid supply outlet port, and the first co part ent..

4. A respiratory regulator as claimed in Claim 3, wherein the first and second compartments communicate by means of a positive pressure flow shut-off port.

5. A respiratory regulator as claimed in Claim 4, wherein during the inspiration phase of the respiration cycle the pressure in the static sensor line decreases, causing the breathing pressure augmentation diaphragm to move toward the static sensor port, thus opening the positive pressure flow shut-off port, which in turn causes pressure above the dragon-fly diaphragm to move upward, thereby opening the fluid supply inlet port.

6. A respiratory regulator as claimed in Claim 5, wherein the opening of the fluid supply inlet port, during inspiration opens fluid communication to the patient of gaseous fluid(s) which exit the respiratory regulator by the fluid supply outlet port and pass through the delivery conduit and cannula for administration of said gaseous fluid(s) .

7. A respiratory regulator as claimed in Claim 4, wherein during the exhalation phase of the respiration cycle the pressure at the static sensor port increases, causing the breathing pressure argumentation diaphragm to move away from the static sensor port, thus closing the positive pressure shut-off port, which in turn causes pressure above the dragon-fly diaphragm to move downward, thereby closing the fluid supply inlet port.

8. A respiratory regulator as claimed in Claim 7, wherein the closing of the fluid supply inlet port, during exhalation prevents fluid administration to the patient.

9. A- espiratory regulator as claimed in Claim 4, wherein if the patient fails to or is unable to exert pressure to the static sensor port, pressure through a small bleed port in the dragon-fly diaphragm causes movement of the breathing pressure augmentation diaphragm toward the static sensor port, opening the positive pressure flow shut-off port, which in turn allows the dragon-fly diaphragm to move away from the fluid supply inlet port, thus opening the fluid supply inlet port.

10. A respiratory regulator as claimed in Claim 9, wnerein the opening of the fluid supply inlet port, opens fluid communication to the patient of gaseous fluid(s) which exit the respiratory regulator by the fluid supply outlet port and pass through tne delivery conduit and cannula for administration of said gaseous fluid(s) during a flush flow condition.

11. A method of regulating the administration of gaseous fluid(s) to a patient, comprising the steps of:

(a) providing a supply of fluid to a patient, and

(b) interrupting the supply when the patients exhalation pressure is greater than a safety margin.