Constant-pressure fluid supply system with multiple fluid capability

• US 6,406,276 B1
• Filed: 03/20/1992
• Issued: 06/18/2002
• Est. Priority Date: 03/04/1986
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Seale, Joseph B., Durand, Kevin, Normand, Gerard B., Kamen, Dean L.
• Primary Examiner(s): FREAY, CHARLES GRANT
• Application Number:
  US07/855,176
• Time in Patent Office: 3,742 Days
• Field of Search: 417/394, 417/395, 417/349, 417/437, 417/478, 417/479
• US Class Current: 417/395
• CPC Class Codes: A61M 2005/1403 Flushing or purging
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 39/22 Valves or arrangement of valves A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405
• CPC Class Codes: A61M 39/24 Check- or non-return valves
• CPC Class Codes: A61M 39/26 Valves closing automatically on disconnecting the line and opening on reconnection thereof check valves A61M39/24
• CPC Class Codes: A61M 39/28 Clamping means for squeezing flexible tubes, e.g. roller clamps tube strippers A61M1/83
• CPC Class Codes: A61M 5/152 pressurised by contraction of elastic reservoirs containers for dispensing contents by contraction of an elastic bag provided therein, in general B65D83/0061
• CPC Class Codes: A61M 5/162 Needle sets, i.e. connections by puncture between reservoir and tube ; Connections between reservoir and tube in jet-action syringes A61M5/30; connectors for tubes having sealed ends and a needle for piercing them A61M39/14
• CPC Class Codes: A61M 5/16809 by repeated filling and emptying of an intermediate volume pressure infusion using positive displacement pumps A61M5/142
• CPC Class Codes: A61M 5/16813 by controlling the degree of opening of the flow line
• CPC Class Codes: A61M 5/16859 Evaluation of pressure response, e.g. to an applied pulse
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: B67D 7/0255 squeezing collapsible or flexible storage containers for dispensing beverages on draught B67D1/0462
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F16K 31/005 Piezoelectric benders
• CPC Class Codes: G01F 1/34 by measuring pressure or differential pressure
• CPC Class Codes: G01F 1/66 by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
• CPC Class Codes: G01F 17/00 Methods or apparatus for determining the capacity of containers or cavities, or the volume of solid bodies measuring linear dimensions to determine volume G01B
• CPC Class Codes: G01P 13/0066 : by using differences of pressure in the fluid
• CPC Class Codes: G05D 16/0641 : the obturator is a membrane
• CPC Class Codes: G05D 16/0647 : using one membrane without spring

Abstract

The invention provides a system for dispensing fluid at relatively constant pressure. In a first embodiment, the invention dispenses a fluid from a chamber of varying dimension defined by a pre-tensioned resilient membrane. In a second embodiment, the invention dispenses a fluid from a chamber defined by a dispensing membrane, which is substantially surrounded by another fluid contained within a pressure chamber of varying dimension defined by a pre-tensioned resilient membrane. In a third embodiment, the invention dispenses multiple fluids, a first fluid from a first dispensing chamber of varying dimension defined by a pre-tensioned resilient membrane, and a second fluid from a dispensing chamber of varying dimension defined by a dispensing membrane substantially surrounded by the first fluid. In a fourth embodiment the invention dispenses multiple fluids from at least two dispensing chambers of varying dimension each substantially surrounded by the pressure fluid contained within a pressure chamber of varying dimension defined by a pre-tensioned resilient membrane. In a preferred embodiment, the resilient membrane is pre-tensioned beyond the point at which, as fluid enters the volume contained by the membrane and the volume increases, the first derivative of pressure over volume becomes zero for the first time.

Claims

1. A system for dispensing a liquid at relatively constant pressure, comprising:

a generally hemispherical mandrel having a curved portion and a foot;

a resilient membrane attached to the foot of the mandrel and stretched over the mandrel'"'"'s curved portion, so as to provide a chamber of varying dimension between the membrane and the mandrel for holding the liquid, the resilient membrane having an inner face, exposed to the chamber, and an outer face, exposed to air; and

a conduit for dispensing the liquid from the chamber;

wherein the mandrel and the membrane are attached so that the membrane is under tension regardless of the volume of the chamber, and so that, as the liquid is introduced into the chamber between the membrane and the mandrel, the shape of the membrane evolves from a generally hemispherical shape towards a generally spherical shape.

2. A system for dispensing a liquid at relatively constant pressure, comprising:

a generally hemispherical mandrel;

a resilient membrane attached to the mandrel under tension so as to provide a chamber of varying volume between the membrane and the mandrel for holding the liquid; and

a conduit for dispensing the liquid from the chamber;

wherein the mandrel and the membrane are attached so that the membrane is under tension regardless of the volume of the chamber, so as to create a greater-than-ambient pressure within the volume, and wherein the resilient membrane is pre-tensioned beyond the point of smallest volume at which the first derivative of pressure over volume is zero.

3. A system for dispensing first and second liquids, comprising:

a resilient flexible membrane defining an outer chamber of varying volume, the membrane having an inner face, exposed to the outer chamber, and an outer face, exposed to ambient pressure;

wherein the first liquid is disposed in sufficient quantity within the outer chamber so as to stretch the resilient membrane and put it under tension, such that the resilient membrane under tension creates in the first liquid a greater-than-ambient pressure;

an inner chamber of varying dimension for containing the second liquid, the inner chamber being disposed within the outer chamber, so that the greater-than-ambient pressure created by the stretched membrane is imparted to the second liquid in the inner chamber;

a first conduit for dispensing the first liquid from the outer chamber;

a second conduit for dispensing the second liquid from the inner chamber;

an output manifold; and

switch means, disposed between the output manifold and the first and second conduits, for serially permitting the liquids from the inner and outer chambers to flow into the output manifold;

wherein the membrane becomes less stretched as the liquids flow from the chambers.

4. A system according to claim 3, wherein the resilient membrane is pre-tensioned beyond the point of smallest volume at which the first derivative of pressure over total volume is zero.

5. A system according to claim 3, wherein the pressure in the chambers is substantially the same.

6. A system for dispensing different multiple fluids sequentially, comprising:

a resilient membrane defining a first volume of varying dimension for holding one of the multiple fluids;

at least one additional volume of varying dimension, disposed within the first volume, for holding another of the multiple fluids;

a first fluid conduit for dispensing fluid from the first volume;

a second fluid conduit for dispensing fluid from the additional volume;

an output manifold; and

switch means, disposed between the output manifold and the fluid conduits, for serially permitting the fluids from the first volume and the additional volume to flow into the output manifold;

wherein the membrane is mounted so that, at all times when the first volume contains one of the multiple fluids, the resilient membrane is stretched, wherein the stretching of the membrane pressurizes the fluid in the first volume and the fluid in the additional volume, and wherein the membrane becomes less stretched as the liquids flow from the chambers.

7. A system according to claim 6, wherein the resilient membrane is pre-tensioned beyond the point of smallest volume at which the first derivative of fluid pressure over total fluid volume is zero.

8. A system according to claim 6 wherein the pressure in the volumes is substantially the same.

9. A system according to claim 6, wherein the switch means includes at least two compressed spring-loaded ball valves disposed in the conduits, wherein each spring-loaded ball valve requires a different force to be opened up.

10. A system according to claim 6, wherein the switch means includes a one-way threshold valve in fluid communication between the conduit of the first volume and the manifold and another one-way threshold valve between the conduit of the additional volume and the manifold.

11. A system according to claim 6, wherein the switch means includes at least one duck-bill valve between at least one of the conduits and the output manifold.

12. A system for dispensing multiple fluids sequentially, comprising:

a resilient membrane defining a first volume of varying dimension for holding one of the multiple fluids;

a fluid conduit for dispensing fluid from the first volume;

a plurality of additional volumes for holding one of the multiple fluids, wherein each of the additional volumes is of varying dimension and disposed within the first volume;

a plurality of fluid conduits for dispensing fluid from each of the additional volumes;

an output manifold; and

switch means, disposed between the output manifold and the fluid conduits, for serially permitting the fluids from the first volume and the additional volumes to flow into the output manifold.

13. A system according to claim 12, wherein the switch means includes a one-way threshold valve in fluid communication between the conduit of the first volume and the manifold and between the conduit of each additional volume and the manifold.

14. A system according to claim 12, wherein the pressure in the volumes is substantially the same.

15. A system according to claim 12, wherein the switch means includes at least two compressed spring-loaded ball valves disposed in the conduits, wherein each spring-loaded ball valve requires a different force to be opened up.

16. A system according to claim 12, wherein the resilient membrane is pre-tensioned beyond the point of smallest volume at which the first derivative of fluid pressure over total fluid volume is zero.

17. A system according to claim 12, wherein the switch means includes at least one duck-bill valve between at least one of the conduits and the output manifold.

18. A system for dispensing multiple dispensable fluids sequentially, comprising:

a resilient membrane;

means for mounting the resilient membrane so as to provide a pressure chamber of varying dimension, and so as to stretch the resilient membrane and put it under tension;

at least two volumes of varying dimension for holding the dispensable fluids, each volume being disposed within the pressure chamber, each volume being in fluid communication with a fluid output;

an output manifold; and

switch means, disposed between the output manifold and each of the fluid outputs, for serially permitting the fluids from the volumes to flow into the output manifold.

19. A system according to claim 18, wherein the resilient membrane is pre-tensioned beyond the point of smallest dimension at which the first derivative of fluid pressure over total fluid volume is zero.

20. A system according to claim 18 where the pressure in the volumes is substantially the same.

21. A system according to claim 18, wherein the switch means includes a one-way threshold valve in fluid communication between each of the fluid outputs and the manifold.

22. A device according to claim 18 wherein the means for mounting the resilient membrane includes a generally hemispherical mandrel having a curved portion and a foot, wherein the resilient membrane is attached to the foot of the mandrel and stretched over the mandrel'"'"'s curved portion, so as to form the pressure chamber between the membrane and the mandrel, and so that as fluid is introduced into the pressure chamber, the shape of the membrane evolves from a generally hemispherical shape to a generally spherical shape.

23. A system according to claim 18, wherein the switch means includes at least two compressed spring-loaded ball valves disposed in the conduits, wherein each spring-loaded ball valve requires a different force to be opened up.

24. A system according to claim 18 wherein the switch means includes at least one duck-bill valve between at least one of the conduits and the output manifold.

25. A system for dispensing multiple dispensable fluids sequentially, comprising:

a resilient membrane;

means for mounting the resilient membrane so as to provide a pressure chamber of varying dimension;

at least two dispensable fluid chambers of varying dimension, each disposed within the pressure chamber, each having a fluid output;

an output manifold; and

switch means for serially switching the outputs from the at least two dispensable chambers into the output manifold, wherein the fluid output includes a spring-loaded ball valve having a preload, and the switch means includes a post, disposed in the output manifold, the post sized and positioned such that the preload is in fixed relation to the height of the post.

26. A system according to claim 25, wherein the spring-loaded ball valve includes a ball seat having a chamfered face.

27. A system according to claim 25, wherein the pressure in the chambers is substantially the same.

28. A system for dispensing two dispensable fluids sequentially, comprising:

means for pressurizing a pressure chamber;

first and second volumes of varying dimension for holding the dispensable fluids, each volume being disposed within the pressure chamber so that the pressure within each of the two volumes is substantially the same;

an output manifold;

first and second fluid outputs providing fluid communication from first and second volumes respectively to the output manifold;

first and second one-way valves disposed in first and second fluid outputs respectively for preventing flow from the output manifold to the volumes and for permitting flow from the volumes to the output manifold when a pressure-differential threshold between the volume and the output manifold is reached, the first one-way valve having a smaller threshold than the second one-way valve so that fluid flows from the first volume to the output manifold before fluid flows from the second volume to the output manifold.

29. A device for pumping fluids which comprises:

a housing having a first fluid port, said housing being formed with a surface having a periphery and a predetermined contour circumscribed by said periphery; and

an elastomeric membrane attached to said periphery over said contour surface to stretch said membrane into a nonlinear region of elasticity and create a potential chamber between said stretched membrane and said housing for receiving fluid therein through said first port and expelling fluid therefrom through a second port by nonlinear contraction of said membrane at a substantially constant pressure.

30. A device according to claim 29 wherein the surface having a periphery includes a generally hemispherical mandrel, and wherein the elastomeric membrane is attached to the mandrel and stretched over the mandrel, so as to form the potential chamber between the member and the mandrel.

31. A device according to claim 30, wherein the shape of the membrane evolves from a generally hemispherical shape to a generally spherical shape as fluid is introduced in the potential chamber.

32. A system for dispensing a liquid at relatively constant pressure, comprising:

a generally hemispherical mandrel;

a resilient membrane attached to the mandrel and stretched over the mandrel, so as to provide a chamber of varying dimension between membrane and the mandrel for holding the liquid; and

a conduit for dispensing the liquid from the chamber;

wherein the mandrel and the membrane are attached so that the membrane is under tension regardless of the volume of the chamber; and

so that, as the liquid is introduced into the chamber between the membrane and the mandrel, the shape of the membrane evolves from a generally hemispherical shape towards a generally spherical shape.

33. A system for dispensing a liquid at relatively constant pressure, comprising:

a generally hemispherical mandrel;

a resilient membrane attached to the mandrel under tension so as to provide a chamber of varying volume between the membrane and the mandrel for holding the liquid; and

a conduit for dispensing the liquid from the chamber;

wherein the mandrel and the membrane are attached so that the membrane is under tension regardless of the volume of the chamber.

34. A system according to claim 33, wherein the shape of the membrane evolves from a generally hemispherical shape to a generally spherical shape as fluid is introduced to the chamber.

35. A system for dispensing first and second liquids, comprising:

a resilient flexible membrane defining an outer chamber of varying volume;

wherein the first liquid is disposed in sufficient quantity within the outer chamber so as to stretch the resilient membrane and put it under tension;

an inner chamber of varying dimension for containing the second liquid, the inner chamber being disposed within the outer chamber;

a first conduit for dispensing the first liquid from the outer chamber;

a second conduit for dispensing the second liquid from the inner chamber;

an output manifold; and

first and second one-way valves disposed in first and second conduits respectively, the first one-way valve having a smaller threshold than the second one-way valve.

36. A system for dispensing first and second liquids, comprising:

a resilient flexible membrane defining an outer chamber of varying volume;

wherein the flexible membrane is stretched and put under tension;

an inner chamber of varying dimension for containing the second liquid, the inner chamber being disposed within the outer chamber;

a first conduit for dispensing the first liquid from the outer chamber;

a second conduit for dispensing the second liquid from the inner chamber;

an output manifold; and

valve means, disposed between the output manifold and the first and second conduits, for serially permitting the liquids from the inner and outer chambers to flow into the output manifold.

37. A system according to claim 36, wherein the valve means includes at least one compressed spring-loaded ball valve disposed in at least one of the conduits, the spring-loaded ball valve requiring a predetermined force to open up.

38. A system according to claim 36, wherein the valve means includes a one-way threshold valve in fluid communication between the first conduit and the output manifold and another one-way threshold valve between the second conduit and the output manifold.

39. A system according to claim 36, wherein the valve means includes a duck-bill valve between at least one of the conduit and the output manifold.

40. A system for dispensing first and second liquids, comprising:

a resilient flexible membrane defining an outer chamber of varying volume;

an inner chamber of varying dimension for containing the second liquid, the inner chamber being disposed within the outer chamber;

a first conduit for dispensing the first liquid from the outer chamber;

a second conduit for dispensing the second liquid from the inner chamber;

an output manifold; and

first and second one-way valves disposed in first and second conduits respectively, the first one-way valve having a smaller threshold than the second one-way valve.

41. A system for dispensing first and second liquids, comprising:

a resilient flexible membrane defining an outer chamber of varying volume;

an inner chamber of varying dimension for containing the second liquid, the inner chamber being disposed within the outer chamber;

a first conduit for dispensing the first liquid from the outer chamber;

a second conduit for dispensing the second liquid from the inner chamber;

an output manifold; and

at least two compressed spring-loaded ball valves disposed in the first and second conduits respectively, wherein each spring-loaded ball valve requires a different force to be opened up.

42. A system for dispensing first and second liquids, comprising:

a resilient flexible membrane defining an outer chamber of varying volume;

an inner chamber of varying dimension for containing the second liquid, the inner chamber being disposed within the outer chamber;

a first conduit for dispensing the first liquid from the outer chamber;

a second conduit for dispensing the second liquid from the inner chamber;

an output manifold; and

at least one duck-bill valve between at least one of the conduits and the output manifold.