Blood pumping and processing system

• US 5,242,384 A
• Filed: 03/13/1992
• Issued: 09/07/1993
• Est. Priority Date: 11/13/1989
• Status: Expired due to Fees

• Current Assignee: Davol Incorporated (Becton, Dickinson & Co)
• Original Assignee: Davol Incorporated (Becton, Dickinson & Co)
• Inventors: Kitrilakis, Sotiris, Robinson, Thomas C.
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US07/852,940
• Time in Patent Office: 543 Days
• Field of Search: 604/4-6, 604/30, 604/31, 604/51, 604/52, 604/82, 604/83, 604/118-120, 604/141-146, 604/151-153, 604/269
• US Class Current: 604/6.11
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/3692 Washing or rinsing blood or blood constituents
• CPC Class Codes: A61M 1/631 Emptying the suction container without interrupting suction
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/38 Blood oxygenation
• CPC Class Codes: A61M 60/43 using vacuum at the blood pump, e.g. to accelerate filling
• CPC Class Codes: A61M 60/435 with diastole or systole switching by valve means located between the blood pump and the hydraulic or pneumatic energy source
• CPC Class Codes: A61M 60/508 Electronic control means, e.g. for feedback regulation
• CPC Class Codes: A61M 60/538 Regulation using real-time blood pump operational parameter data, e.g. motor current
• CPC Class Codes: A61M 60/546 of blood flow, e.g. by adapting rotor speed
• CPC Class Codes: A61M 60/554 of blood pressure
• CPC Class Codes: A61M 60/851 Valves

Abstract

Blood is pumped by a pump, preferably a bi-concave diaphragm pump. When the blood pump is full of blood, this full condition is detected and a batch of blood is emptied completely from the pump for delivery to the patient. A second pump, also preferably a bi-concave diaphragm pump, pumps anti-coagulant into the blood as it is recovered. This second pump ejects its contents every time the blood pump ejects its contents. Particulates in the blood are removed by a filter and air is removed by a defoamer. Fluid and very small matter in the blood may be removed in a tangential flow separator. Blood flows through a narrow passage along one or more membranes, with fluid and small matter passing through the membrane(s). A washing fluid may be added to blood within this separator. A third pump, again preferably a bi-concave diaphragm pump, is used to add this washing fluid. The third pump is emptied whenever the blood pump empties, and thereafter refills with washing fluid.

Claims

1. A blood filtering, pumping and tangential flow separating apparatus, comprising:

a filter connected to receive a mixture of blood cells, platelets, blood fluid and particulate matter from a patient and being capable of removing at least a portion of said particulate matter larger than blood cells to form a filtered mixture, said filter having an outlet port from which said filtered mixture exits;

a main pump having a pumping chamber having a pump inlet port arranged to receive said filtered mixture and a pump outlet port from which said filtered mixture is pumped;

valve means between said filter outlet port and said pump inlet port for (1) preventing flow from said pumping chamber back into said filter and (2) allowing flow from said filter outlet port to said pump inlet port when said filtered mixture is not being pumped out of said pump outlet port;

a tangential flow separator having a narrow passage having a porous membrane having an infacing and an outfacing surface and extending along said passage, said passage being no more than about 500 microns across, said passage extending from a separator inlet to a separator outlet;

delivery means for delivering said filtered mixture from said pumping chamber to said separator inlet to provide a pressure in said passage sufficient to impel blood fluid through said porous membrane and a flow rate through said passage sufficient to prevent said blood cells at platelets from blocking or passing through said porous membrane;

fluid removal means for removing blood fluid from said outfacing surface of said membrane, a pressure adjacent said outfacing surface of said membrane being less than the pressure in said passage; and

means for returning the blood cells and platelets from said separator outlet to the patient.

2. An apparatus as set forth in claim 1, further including:

a defoamer having an inlet port for receiving a recovered mixture of said blood cells, platelets, blood fluid, particulate matter and entrapped gases, said defoamer being adapted to remove at least a portion of said entrapped gases from said mixture, said defoamer being connected to deliver said mixture to said filter.

3. An apparatus as set forth in claim 2, wherein said main pump is a main diaphragm pump.

4. An apparatus as set forth in claim 3, wherein said main diaphragm pump pumping chamber is a substantially bi-concave chamber divided by a diaphragm into said pumping chamber and a pressurization subchamber, said diaphragm being movable to define said pumping chamber as substantially equal to the internal volume of said bi-concave chamber;

and further including;

means for pressurizing said pressurization subchamber sufficiently to impel said filtered mixture out of said pump outlet port.

5. An apparatus as set forth in claim 2, further including:

an anti-coagulant pump positioned to deliver anti-coagulant to said recovered mixture prior to its introduction to said defoamer.

6. An apparatus as set forth in claim 5, further including:

means for respectively starting and stopping said anti-coagulant pump in response to starting and stopping of pumping of said main pump.

7. An apparatus as set forth in claim 6, wherein said anti-coagulant pump is an anti-coagulant diaphragm pump.

8. An apparatus as set forth in claim 7, further including:

washing fluid delivery means for delivering washing fluid to said passage.

9. An apparatus as set forth in claim 8, wherein said washing fluid delivery means is a washing fluid pump.

10. An apparatus as set forth in claim 9, further including:

means for respectively starting and stopping said washing fluid pump in response to starting and stopping of pumping by said main pump.

11. An apparatus as set forth in claim 10, wherein said washing fluid pump is a washing fluid diaphragm pump.

12. An apparatus as set forth in claim 1, further including:

washing fluid delivery means for delivering washing fluid to said passage.

13. An apparatus as set forth in claim 12, wherein said washing fluid delivery means is a washing fluid pump.

14. An apparatus as set forth in claim 13, further including:

means for respectively starting and stopping said washing fluid pump in response to starting and stopping of pumping by said main pump.

15. An apparatus as set forth in claim 14, wherein said washing fluid pump is a washing fluid diaphragm pump.

16. An apparatus as set forth in claim 15, wherein said main pump is a main diaphragm pump.

17. An apparatus as set forth in claim 16, wherein said fluid removal means comprises a waste

18. An apparatus as set forth in claim 17, further including

the main pump and the waste pumps each having a fill period and a pumping period;

means for controlling the pumping period of said main pump to be longer than its fill period; and

means for controlling the waste pump to have a fill period corresponding to the main pump pumping period and to have a pumping period corresponding to the main pump fill period.

19. An apparatus as set forth in claim 18, wherein said washing fluid pump and said waste pump pumping volumes are coordinatedly selected to provide a given percent output hematocrit from the separator when the input hematocrit to the main pump is a selected value less than said given percent.

20. An apparatus as set forth in claim 19, wherein said given percent falls within a range from about 40% to about 60% and said selected value falls within a range from about 5% to about 40%.

21. An apparatus as set forth in claim 19, wherein said waste fluid pump pumping volume is fixed and said washing fluid pumping volume is varied to provide the given percent output hematocrit from the separator.

22. An apparatus as set forth in claim 1, wherein the pressure in said narrow passage of the tangential membrane exceeds the pressure adjacent the outfacing surface of the membrane by from about 25 mm Hg to about 150 mm Hg.

23. An apparatus as set forth in claim 1, wherein said valve means is a float valve.

24. An apparatus as set forth in claim 1, further including:

blood collecting means for collecting blood from adjacent a patient and delivering said blood to said inlet port.

25. An apparatus as set forth in claim 24, wherein:

said defoamer and said filter are combined in a single defoaming and filtering unit;

said unit includes an upper chamber having an upper non-liquid filled region; and

wherein said blood collecting means includes a conduit for delivering said recovered mixture to said defoamer and vacuum means for partially evacuating said upper region such that the pressure therein is lower than that of the surrounding atmosphere.

26. An apparatus as set forth in claim 1, further including:

an anti-coagulant pump positioned to deliver anti-coagulant to said blood prior to its introduction to said filter.

27. An apparatus as set forth in claim 26, further including:

means for respectively starting and stopping said anti-coagulant pump in response to starting and stopping of pumping of said main pump.

28. An apparatus as set forth in claim 27, wherein said anti-coagulant pump is an anti-coagulant diaphragm pump.

29. An apparatus as set forth in claim 28, further including:

washing fluid delivery means for delivering washing fluid to said passage.

30. An apparatus as set forth in claim 29, wherein said washing fluid delivery means is a washing fluid pump.

31. An apparatus as set forth in claim 30, further including:

means for respectively starting and stopping said washing fluid pump in response to starting and stopping of pumping by said main pump.

32. An apparatus as set forth in claim 31, wherein said washing fluid pump is a washing fluid diaphragm pump.

33. An apparatus as set forth in claim 26, further including:

anti-coagulant pump accumulator means for accumulating a portion of the anti-coagulant exiting said anti-coagulant pump; and

anti-coagulant metering means for metering said portion of said anti-coagulant to said recovered mixture when said anti-coagulant pump is not delivering anti-coagulant to said recovered mixture.

34. An apparatus as set forth in claim 1, wherein said tangential flow separator includes an additional aqueous solution permeable membrane having an infacing surface and an outfacing surface and extending along said passage;

and further including;

washing fluid delivery means for delivering washing fluid against the outfacing surface of said additional membrane at a pressure sufficiently high whereby said washing fluid passes therethrough and into said passage.

35. An apparatus as set forth in claim 34, wherein said washing fluid delivery means is a washing fluid pump.

36. An apparatus as set forth in claim 35, further including:

means for respectively starting and stopping said washing fluid pump in response to starting and stopping of pumping by said main pump.

37. An apparatus as set forth in claim 1, further including:

main pump accumulator means for accumulating a portion of the filtered mixture exiting said pump outlet port; and

filtered mixture metering means for metering said portion of said filtered mixture to said passage when said main pump is not pumping said filtered mixture out of said pump outlet port.

38. An apparatus as set forth in claim 37, further including:

an anti-coagulant pump positioned to deliver anti-coagulant to said recovered mixture prior to its introduction to said defoamer.

39. An apparatus as set forth in claim 38, further including:

anti-coagulant pump accumulator means for accumulating a portion of the anti-coagulant exiting said anti-coagulant pump; and

anti-coagulant metering means for metering said portion of said anti-coagulant to said recovered mixture when said anti-coagulant pump is not delivering anti-coagulant to said recovered mixture.

40. An apparatus as set forth in claim 39, further including:

washing fluid delivery means for delivering washing fluid to said passage.

41. An apparatus as set forth in claim 40, further including:

washing fluid accumulator means for accumulating a portion of the washing fluid from said washing fluid delivery means; and

washing fluid metering means for metering said portion of said washing fluid to said passage when said washing fluid delivery means is not delivering washing fluid to said passage.

42. An apparatus as set forth in claim 37, further including:

washing fluid delivery means for delivering washing fluid to said passage.

43. An apparatus as set forth in claim 42, further including:

washing fluid accumulator means for accumulating a portion of the washing fluid from said washing fluid delivery means; and

washing fluid metering means for metering said portion of said washing fluid to said passage when said washing fluid delivery means is not delivering washing fluid to said passage.

44. An apparatus as set forth in claim 1, further including:

washing fluid delivery means for delivering washing fluid to said passage.

45. An apparatus as set forth in claim 44, further including:

washing fluid accumulator means for accumulating a portion of the washing fluid from said washing fluid delivery means; and

washing fluid metering means for metering said portion of said washing fluid to said passage when said washing fluid delivery means is not delivering washing fluid to said passage.

46. An apparatus as set forth in claim 1, further including:

bypass means for bypassing said filtered mixture exiting said pump outlet port around said tangential flow separator in response to the flow rate from said pump outlet port exceeding the flow through capacity of said tangential flow separator.

47. An apparatus as set forth in claim 1, further including:

oscillation generating means for generating oscillations in said passage.

80. An apparatus as set forth in claim 17 wherein the waste pump is a waste diaphragm pump.

48. A blood pumping and fluid introduction apparatus, comprising:

a main pump having a pumping subchamber having a pump inlet port arranged to receive blood and a pump outlet port from which said blood is pumped, said main pump having a substantially biconoave main pump chamber divided by a main pump diaphragm into said pumping subchamber and a pressurization subchamber;

a blood delivery system for delivering blood to said pump inlet port;

valve means between said blood delivery system and said pump inlet port for (1) preventing flow from said pumping subchamber back into said blood delivery system and for (2) allowing flow from said blood delivery system to said pump inlet port when blood is not being pumped out of said pump outlet port;

means for determining when said main pump pumping subchamber is substantially full;

main pump pressurizing means for pressurizing said main pump pressurization subchamber, in response to said main pump pumping subchamber being substantially full, sufficiently to impel substantially all of said blood out of said pump outlet port;

a fluid introduction pump positioned to deliver a fluid to said blood; and

means for respectively starting and stopping said fluid introduction pump in response respectively to starting and stopping of pumping of said main pump.

49. An apparatus as set forth in claim 48, wherein said blood is a portion of a recovered mixture which includes healthy blood cells, platelets, plasma and particulate matter, and wherein said blood delivery system includes a filter connected to receive said recovered mixture and being capable of removing at least a portion of said particulate matter to form a filtered mixture, said filter having an outlet port from which said filtered mixture exits.

50. An apparatus as set forth in claim 49, wherein said blood delivery system further includes a defoamer having an inlet port for receiving said recovered mixture and being capable of removing at least a portion of any entrapped gases therefrom and delivering a resulting defoamed mixture to said filter.

51. An apparatus as set forth in claim 50, wherein said blood delivery system further includes blood and particulate matter collecting means for collecting blood and particulate matter from adjacent a patient and delivering said blood and particulate matter to said inlet port.

52. An apparatus as set forth in claim 51, wherein:

said defoamer and said filter are combined in a single defoaming and filtering unit;

said unit includes an upper chamber having an upper non-liquid filled region; and

wherein said blood and particulate matter collecting means includes a conduit for delivering said recovered mixture to said defoamer and vacuum means for partially evacuating said upper region such that the pressure therein is lower than that of the surrounding atmosphere.

53. An apparatus as set forth in claim 48, wherein said fluid pump has a substantially biconcave chamber divided by a diaphragm into a fluid pump pumping subchamber and a fluid pump pressurization subchamber and wherein said main pump pressurizing means, simultaneously with pressurizing said bi-concave main pump pressurization subchamber, also pressurizes said fluid pump pressurization subchamber sufficiently to substantially empty said fluid from said fluid pump pumping subchamber.

54. An apparatus as set forth in claim 53, wherein said fluid delivered by said fluid introduction pump comprises anti-coagulant.

55. A blood pumping and processing apparatus comprising:

a rigid main pump housing having an internal wall structure defining a bi-conoave chamber;

a main pump diaphragm sealed at its periphery to said internal wall structure, said main pump diaphragm dividing said chamber into a pressurization subchamber and a stroking subchamber, said diaphragm being of a shape and size sufficient to fit substantially matingly against said internal wall structure defining either of said subchambers and being formulated of a material which is sufficiently flexible to allow said diaphragm to fit substantially matingly against said internal wall structure defining each of said subchambers whereby by diaphragm motion and flexing each of said subchambers can vary in size from substantially zero volume to substantially the volume of said chamber;

inlet valve means for delivering blood to said stroking subchamber and for preventing backflow therethrough;

outlet valve means for permitting blood to leave said stroking subchamber and for preventing flow back into the stroking subchamber;

means for pressurizing said pressurization subchamber at a controlled rate sufficiently to motivate said diaphragm to substantially matingly fit against said internal wall structure defining said stroking subchamber to expel substantially all blood in said stroking subchamber through said outlet valve means;

means for depressurizing said pressurization subchamber at a controlled rate sufficiently to motivate said diaphragm to substantially matingly fit against said internal wall structure defining said pressurization subchamber;

means for sensing when said stroking subchamber is substantially full and for activating said pressurizing means when said stroking subchamber is substantially full; and

means for processing blood flowing to or from said main pump.

56. An apparatus as set forth in claim 55, wherein said means for sensing when said stroking subchamber is substantially full includes means for detecting the change in pressure in said pressurization subchamber as a pressurizing gas is added thereto.

57. An apparatus as set forth in claim 56, wherein said inlet valve means comprises a float valve having a float having a specific gravity between about 0.8 and 1.0.

58. An apparatus as set forth in claim 55, further including:

means for periodically activating said pressurization means;

means for detecting the rate of increase in pressure in said pressurization subchamber on activating of said periodic activating means; and

means for aborting operation of said pressurizing means if said rate of increase in pressure in said pressurization subchamber is less than a selected value representative of said float valve being closed.

59. An apparatus as set forth in claim 55, wherein said blood processing means removes or modifies a component of the blood.

60. An apparatus as set forth in claim 55, wherein said blood processing means removes components larger than red cells from said blood.

61. An apparatus as set forth in claim 60, wherein said blood processing means comprises a tangential flow separator for removing components smaller than red cells and platelets via a porous membrane.

62. An apparatus as set forth in claim 55, wherein said blood processing means comprises a tangential flow separator for removing components smaller than red cells and platelets via a porous membrane.

63. A method of separating blood cells from blood plasma, comprising:

filtering and defoaming a recovered mixture of healthy blood cells, platelets, plasma, particulate matter and entrapped gases to remove at least a portion of said particulate matter therefrom and at least a portion of the entrapped gases to form a defoamed and filtered mixture;

pumping said defoamed and filtered mixture into an inlet of a tangential flow separator having a narrow flow through passage having a porous membrane having an infacing surface and an outfacing surface and extending along the passage, the passage being no more than about 500 microns across, said passage extending from said separator inlet to a separator outlet, said pumping providing a pressure within said passage sufficient to impel plasma through the porous membrane and a flow rate through the passage sufficient to prevent the blood cells from blocking or passing through the porous membrane; and

removing plasma from the outfacing surface of the membrane by maintaining a pressure adjacent said outfacing surface of said membrane as less than that in the passage.

64. A method as set forth in claim 63, further including:

delivering washing fluid to said passage.

65. A method as set forth in claim 64, further including starting and stopping delivery of said washing fluid substantially simultaneously with starting and stopping of pumping of said defoamed and filtered mixture.

66. A method as set forth in claim 65, further including:

delivering anti-coagulant to said recovered mixture prior to its defoaming.

67. A method as set forth in claim 66, further including:

starting and stopping delivery of said anti-coagulant substantially simultaneously with starting and stopping of pumping of said defoamed and filtered mixture.

68. A method as set forth in claim 63, further including:

delivering anti-coagulant to said recovered mixture prior to its defoaming.

69. A method as set forth in claim 68, further including:

starting and stopping delivery of said anti-coagulant substantially simultaneously with starting and stopping of pumping of said defoamed and filtered mixture.

70. A method as set forth in claim 63, wherein said tangential flow separator includes an additional membrane having an infacing surface and an outfaoing surface and extending along the passage, and further including:

delivering washing fluid against the outfacing surface of said additional membrane at a pressure sufficiently high whereby said washing fluid passes therethrough and into said passage.

71. A method as set forth in claim 70, further including starting and stopping delivery of said washing fluid substantially simultaneously with starting and stopping of pumping of said defoamed and filtered mixture.

72. A method as set forth in claim 71, further including:

delivering anti-coagulant to said recovered mixture prior to its defoaming.

73. A method as set forth in claim 72, further including:

starting and stopping delivery of said anti-coagulant substantially simultaneously with starting and stopping of pumping of said defoamed and filtered mixture.

74. A blood pumping and treating apparatus, comprising:

a main pump having a pumping subchamber having a pump inlet port arranged to receive blood and a pump outlet port from which said blood is pumped;

a blood delivery system for delivering blood to said pump inlet port;

valve means between said blood delivery system and said pump inlet port for (1) preventing flow from said pumping subchamber back into said blood delivery system and for (2) allowing flow from said blood delivery system to said pump inlet port when blood is not being pumped out of said pump outlet port;

means for determining when said main pump pumping subchamber is substantially full;

means for activating said pump to pump blood out of said main pump pumping subchamber in response to said main pump pumping subchamber being substantially full sufficiently to impel substantially all of said blood out of said pump outlet port;

a wash fluid pump positioned to deliver wash fluid to said blood;

means for determining inlet blood hematocrit to said main pump pumping subchamber; and

means for controlling delivery of fluid by said wash fluid pump as a function of inlet blood hematocrit to be in an amount to provide output blood hematocrit following introduction of said wash fluid which falls within a selected range.

75. An apparatus as set forth in claim 74, further including:

means for delivering the outlet blood to a patient.

76. An apparatus as set forth in claim 74, further including:

a tangential flow separator having a narrow passage having a porous membrane having an infacing and an outfacing surface and extending along said passage, said passage being no more than about 500 microns across, said passage extending from a separator inlet to a separator outlet;

delivery means for delivering said filtered mixture from said pumping subchamber to said separator inlet to provide a pressure in said passage sufficient to impel blood fluid through said porous membrane and a flow rate through said passage sufficient to prevent said blood cells and platelets from blocking or passing through said porous membrane;

fluid removal means for removing blood fluid from said outfaoing surface of said membrane, a pressure adjacent said outfacing surface of said second membrane being less than the pressure in said passage; and

means for delivering the blood cells and platelets from said separator outlet to a patient.

77. An apparatus as set forth in claim 76, wherein said fluid removal means comprises a waste pump, and wherein said main pump and said waste pump each are diaphragm pumps and each having a fill period and a pumping period;

and further including;

means for controlling the pumping period of said main pump to be longer than its fullperiod; and

means for controlling the waste pump to have a fill period corresponding to the main pump pumping period and to have a pumping period corresponding to the main pump fill period.

78. An apparatus as set forth in claim 77, wherein said washing fluid pump and said waste pump pumping volumes are coordinatedly selected to provide a given percent output hematocrit from the separator when the input hematocrit to the main pump is a selected value less than said given percent.

79. An apparatus as set forth in claim 78, wherein said given percent falls within a range from about 40% to about 60% and said selected value falls within a range from about 5% to about 40%.