Pump chamber configured to contain a residual fluid volume for inhibiting the pumping of a gas

• US 9,494,150 B2
• Filed: 08/22/2013
• Issued: 11/15/2016
• Est. Priority Date: 07/20/1999
• Status: Expired due to Fees

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Gray, Larry B., Bryant, Robert J. Jr., Spencer, Geoffrey P.
• Primary Examiner(s): Fristoe, Jr., John K
• Assistant Examiner(s): Rost, Andrew J
• Application Number:
  US13/973,630
• Publication Number:
  US 20130343936A1
• Time in Patent Office: 1,181 Days
• Field of Search: 251/61.1, 251/128, 417/477.2, 417/477.1, 417/395, 417/394, 417/392, 417/476, 417/474, 277/646, 604/153
• US Class Current: 1/1
• CPC Class Codes: A61M 1/1649 with pulsatile dialysis fluid flow
• CPC Class Codes: A61M 1/267 used for pumping
• CPC Class Codes: A61M 1/362227 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/362261 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/362265 Details of valves
• CPC Class Codes: A61M 1/362266 Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/367 Circuit parts not covered by the preceding subgroups of group A61M1/3621
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2209/02 Equipment for testing the apparatus
• CPC Class Codes: A61M 39/228 with a tubular diaphragm constrictable by radial fluid force
• CPC Class Codes: A61M 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/14593 the diaphragm being actuated by fluid pressure
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: F04B 43/067 the fluid being actuated directly by a piston
• CPC Class Codes: F04B 45/00 Pumps or pumping installations having flexible working members and specially adapted for elastic fluids
• CPC Class Codes: F04B 45/02 having bellows
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 49/12 : by varying the length of stroke of the working members
• CPC Class Codes: F04B 53/10 : Valves; Arrangement of valves
• CPC Class Codes: F04B 53/16 : Casings; Cylinders; Cylinder liners or heads; Fluid connections
• CPC Class Codes: G01M 3/26 : by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
• CPC Class Codes: G01M 3/32 : for containers, e.g. radiators
• CPC Class Codes: G05D 16/20 : characterised by the use of electric means

Abstract

The present invention involves, in some embodiments, medical systems for pumping fluid using a medical-grade cartridge configured for use in a reusable fluid medical apparatus to move liquids through the cartridge. The cartridge includes a membrane defining a chamber. The system includes a pressure source able to be placed in pneumatic communication with the chamber to adjust gas pressure therein. The system further includes a processor configured to perform a dry integrity test based on adjustment and measurement of fluid pressures in the chamber in which neither side of the member is exposed to liquid during test to determine whether a fluid leak exists through the membrane.

Claims

1. A medical system for pumping fluid using a medical-grade cartridge configured for use in a reusable fluid medical apparatus to move liquids through the cartridge, comprising:

the medical-grade cartridge having a membrane defining a first chamber when mated to the reusable fluid medical apparatus;

a pressure source configured to be capable of being in pneumatic communication with the first chamber, wherein the pressure source is configured to adjust pressure of a gas capable of being in pneumatic communication with the membrane;

a pressure transducer configured to measure a pressure in operative communication with the pressure source;

a valve configured to isolate the first chamber from the pressure source and operatively connect the pressure source to the first chamber; and

a processor of the medical system configured to perform a dry integrity test in which neither side of the membrane is exposed to liquid during the dry integrity test and in which the first chamber is in fluid communication with the surroundings of the cartridge, the processor configured to;

actuate the valve between a first position and a second position;

adjust the pressure of the fluid of the pressure source;

measure a first pressure of the pressure transducer to generate a first pressure value when the valve is in the first position;

measure a second pressure of the pressure transducer to generate a second pressure value after the valve is in the second position; and

determine whether a fluid leak exists through the membrane based on a pressure difference indicated by the first and second pressure values.

2. The system according to claim 1, wherein the valve is configured such that the first position blocks the fluid path.

3. The system according to claim 2, wherein the processor is configured to measure the first pressure to generate the first pressure value after the pressure from the pressure source is adjusted.

4. The system according to claim 3, wherein the pressure source includes a tank.

5. The system according to claim 3, wherein the processor measures the second pressure to generate the second pressure value after the valve unblocks the first chamber from the pressure source.

6. The system according to claim 1, wherein the second position of the valve unblocks the first chamber from the pressure source.

7. The system according to claim 1, wherein the second position of the valve fluidly connects the pressure source to the cartridge.

8. The system according to claim 1, wherein the second position of the valve fluidly connects the pressure source to the first chamber of the cartridge.

9. The system according to claim 1, wherein the membrane defines a second chamber.

10. The system according to claim 9, wherein the fluid leak is determined as a leakage rate of fluid through the membrane between the first chamber and the second chamber.

11. The system according to claim 10, wherein the leakage rate is a leakage rate through a portion of the membrane that only separates the first chamber from the second chamber.

12. The system according to claim 9, wherein the first chamber and the second chamber define a pump.

13. The system according to claim 9, wherein the first chamber and the second chamber define a valve.

14. The system according to claim 1, wherein the first pressure value is a pressure measurement.

15. The system according to claim 1, wherein the second pressure value is another pressure measurement.

16. The system according to claim 1, wherein a first set of multiple timed intervals is used to generate the first pressure value.

17. The system according to claim 1, wherein a second set of multiple timed intervals is used to generate the second pressure value.

18. The system according to claim 1, wherein the pressure transducer continuously monitors the pressure to generate the first and second pressure values.

19. The system according to claim 1, wherein the pressure transducer continuously monitors the pressure over a predetermined period of time to generate the first pressure value.

20. The system according to claim 19, wherein the pressure transducer continuously monitors the pressure over another predetermined period of time to generate the second value.

21. The system according to claim 1, wherein the pressure transducer continuously monitors the pressure over a predetermined period of time to generate the second value.

22. The system according to claim 1, wherein the source supplies a positive pressure.

23. The system according to claim 1, wherein the source supplies a negative pressure.

24. The system according to claim 1, wherein the system is configured such that the valve is capable of connecting the cartridge to the cartridge'"'"'s surroundings.

25. The system according to claim 1, wherein the processor is configured to cause a fault if a change in pressure as indicated by the first and second values exceeds a predetermined limit.

26. The system according to claim 25, wherein the predetermined limit is a maximum allowable predetermined limit.

27. The system according to claim 1, wherein the processor is configured to terminate operation when a change in pressure as indicated by the first and second values exceeds a predetermined limit.

28. The system according to claim 27, wherein the change in pressure is used to determine whether the fluid leak exists.

29. The system according to claim 1, wherein the processor calculates a leakage rate to determine whether a fluid leak exists through the membrane.

30. The system according to claim 1, wherein the processor uses the pressure difference to calculate a leakage rate.

31. The system according to claim 1, wherein the processor performs a dry cartridge integrity test to determine whether a fluid leak exists through the membrane.

32. The system according to claim 1, wherein the pressure transducer is resident on a circuit board having a processor.

33. The system according to claim 1, wherein fluid communication between the pressure source and the first chamber includes a tube.

34. The system according to claim 1, wherein fluid communication between the pressure source and the first chamber includes a channel.

35. The system according to claim 1, wherein fluid communication between the pressure source and the first chamber includes a line and a port.

36. The system according to claim 1, wherein the cartridge includes an inlet or an outlet apparatus for blocking fluid flow to and from a second chamber defined by the membrane, wherein the second chamber is on an opposing side of the membrane relative to the first chamber.

37. The system according to claim 36, wherein at least one of the inlet or output apparatus is configured to isolate at least one of the first chamber and the second, chamber from a flow path of the cartridge.

38. The system according to claim 1, wherein the processor is configured to perform a dry pumping integrity test after coupling the cartridge to a reusable component and before priming the cartridge with a liquid.

39. The system according to claim 1, wherein the cartridge is a pumping cartridge.

40. The system according to claim 1, wherein the cartridge is a cassette.

41. The system according to claim 1, wherein the cartridge is a pumping cartridge comprising a substantially rigid component with one or more depressions and channels therein covered on at least one side by the membrane.

42. The system according to claim 41, wherein the membrane is hermetically sealed to the substantially rigid component.

43. The system according to claim 1, wherein the membrane is a flexible membrane.

44. The system according to claim 1, wherein a first and second set of multiple timed intervals are used to determine whether the fluid leak exists.

45. The system according to claim 1, wherein a leakage rate is calculated based upon a blocked pressure and an unblocked pressure.

46. The system according to claim 1, wherein a membrane leak rate is used by the processor to determine whether the fluid leak exists through the membrane.

47. The system according to claim 1, wherein the processor receives a pressure signal from the pressure transducer.

48. The system according to claim 1, wherein the processor uses the determination of whether the fluid leak exists to determine whether a membrane puncture has occurred.

49. The system according to claim 1, wherein the membrane defines a second chamber on an opposite side of the membrane relative to the first chamber, wherein the first chamber is coupled to a pressure tank via a fluid path, and wherein the pressure source includes the pressure tank.

50. The system according to claim 1, wherein the pressure source is a pressure tank and the pressure transducer is operatively disposed within the pressure tank to measure the pressure within the pressure tank.

51. The system according to claim 50, wherein the valve is disposed between the chamber and the pressure tank, wherein the system further comprises a valve controller connected to the valve, a pump connected to the pressure tank, and the processor is connected to the pressure transducer, to the pump, and to the valve controller.

52. The system according to claim 51, wherein the processor determines if the difference is greater than a critical leak rate.

53. The system according to claim 52, wherein when the processor determines that the difference is greater than the critical leak rate, the processor initiates an alarm sequence.

54. The system according to claim 53, wherein the alarm sequence includes activating an auditory indicator.

55. The system according to claim 53, wherein the alarm sequence includes activating a visual indicator.

56. The system according to claim 53, wherein the alarm sequence includes a shutdown procedure configured to prevent faulty flow.

57. The system according to claim 1, wherein the processor is configured to use the difference to determine if the membrane is defective before the membrane is used for pumping a transport fluid.

58. The system according to claim 1, wherein the system is a dialysis system.

59. A medical system for pumping fluid using a medical-grade cartridge, comprising:

the medical-grade cartridge having a membrane defining a chamber when the cartridge is mounted in the medical system;

a pressure source configured to be capable of applying a pressure within the pressure source to the membrane when the pressure source is in fluid communication with the membrane, wherein the pressure source is configured to adjust pressure of a fluid that is capable of being in fluid communication with the membrane;

a pressure transducer configured to measure a pressure in operative communication with the pressure source; and

a valve configured to isolate the chamber from the pressure source and operatively connect the pressure source to the chamber thereby fluidly connecting the pressure source to the membrane;

a processor of the medical system configured to perform a dry integrity test of the cartridge before allowing liquid to enter the cartridge and in which the cartridge is in fluid communication with the surroundings of the cartridge, the test comprising;

actuating the valve between a first position and a second position;

adjusting the pressure of the fluid of the pressure source;

measuring a first pressure of the pressure transducer to generate a first pressure value;

measuring a second pressure of the pressure transducer to generate a second pressure value; and

determining whether a fluid leak exists through the membrane based on a pressure difference indicated by the first and second pressure values.

60. The system according to claim 59, wherein the processor is configured to adjust the pressure of the fluid of the pressure source, actuate the valve, and measure the first and second pressures to determine whether a fluid leak exists.

61. The system according to claim 59, wherein the processor is configured to measure the first pressure after the valve has been actuated to the first position.

62. The system according to claim 59, wherein the first position allows the pressure within the chamber to equalize to the pressure of the pressure source.

63. The system according to claim 59, wherein the processor is configured to measure the second pressure after the valve has been actuated to the second position.

64. The system according to claim 63, wherein the second position is configured to allow the processor to determine if a leak exists within the membrane such that the second pressure value corresponds to a leak of the membrane.

65. A medical system for pumping fluid using a medical-grade cartridge, comprising:

the medical-grade cartridge having a membrane defining a chamber when the cartridge is coupled to the medical system;

a pressure source configured to be capable of applying a pressure within the pressure source to the membrane when the pressure source is in fluid communication with the membrane, wherein the pressure source is configured to adjust pressure of a fluid that is capable of being in fluid communication with the membrane;

a pressure transducer configured to measure a pressure in operative communication with the pressure source; and

a valve configured to isolate the chamber from the pressure source and operatively connect the pressure source to the chamber thereby fluidly connecting the pressure source to the membrane;

a processor of the medical system configured to perform a dry integrity test of the cartridge before allowing liquid to enter the cartridge and in which the cartridge is in fluid communication with the surroundings of the cartridge, the test comprising;

actuating the valve between a first position and a second position;

adjusting the pressure of the fluid of the pressure source;

measuring a first pressure of the pressure transducer;

measuring a second pressure of the pressure transducer; and

applying leak-determining means to determine if a leak exists within the membrane.

66. The system according to claim 65, wherein the leak-determining means utilizes the first and second pressures of the pressure transducer.

67. The system according to claim 66, wherein the first and second pressures are assumed to be static pressure values.

68. The system according to claim 65, wherein the leak-determining means utilizes the valve.