Blood Processing Systems And Methods That Employ An In-Line Flexible Leukofilter

• US 20090194489A1
• Filed: 02/25/2009
• Published: 08/06/2009
• Est. Priority Date: 09/03/1999
• Status: Abandoned Application

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Smith, Kelly B., Vandlik, Mark R., Westberg, Tom, Vishnoi, Rohit, Kast, Michael J
• Application Number:
  US12/392,769
• Publication Number:
  US 20090194489A1
• Time in Patent Office: Days
• US Class Current: 210/808
• CPC Class Codes: A61M 1/00 Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems catheters A61M25/00; tube connectors, tube couplings, valves or branch units specially adapted for medical use A61M39/00; devices for taking samples of blood A61B5/15; filters implantable into blood vessels A61F2/01
• CPC Class Codes: A61M 1/0209 Multiple bag systems for separating or storing blood components
• CPC Class Codes: A61M 1/0218 with filters
• CPC Class Codes: A61M 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/302 having a reservoir for withdrawn untreated blood
• CPC Class Codes: A61M 1/303 having a reservoir for treated blood to be returned
• CPC Class Codes: A61M 1/308 Volume control, e.g. with open or flexible containers, by counting the number of pump revolutions, weighing
• 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 1/362265 Details of valves
• CPC Class Codes: A61M 1/362266 Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/3633 Blood component filters, e.g. leukocyte filters
• CPC Class Codes: A61M 1/3636 having a flexible housing
• CPC Class Codes: A61M 1/3693 using separation based on different densities of components, e.g. centrifuging
• CPC Class Codes: A61M 1/3696 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/331 used as turbidity change detectors, e.g. for priming-blood or plasma-hemoglubine-interface detection
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: A61M 60/113 : in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/43 : using vacuum at the blood pump, e.g. to accelerate filling

Abstract

Systems and methods separate pump the blood cells through an in-line leukofilter to a blood cell storage container. The leukofilter has a filtration medium enclosed within a flexile housing. The systems and methods can employ a fixture to restrain expansion of the flexible filter housing during operation of the pump.

Claims

1-8. -8. (canceled)

9. A blood processing system comprising

a blood processing set including a source of blood cells, and a blood component collection flow channel coupled to the source of blood cells including a blood cell storage container and an in-line filter to remove leukocytes from the blood cells before entering the blood cell storage container, the in-line filter including a leukocyte removal filter medium and first and second flexible housings, wherein the flexible housings are comprised of DEHP-free plastic material, and

a pump station adapted to be placed into communication with the blood component collection flow channel to pump blood into the blood cell storage container through the in-line filter.

10. The blood processing system of claim 9 wherein said leukocyte removal filter medium comprises a plurality of layers.

11. The blood processing system of claim 9 wherein said leukocyte removal filter medium comprises a leukocyte-exclusion filter medium including a membrane.

12. The blood processing system of claim 9 wherein said leukocyte removal filter medium comprises a depth filtration filter comprising a fibrous filter medium.

13. In a method of filtering a liquid using a filter comprising a flexible housing having an inlet port and outlet port for the liquid and a sheet-like filter element for removing undesired components from the liquid, with the inlet port being separated from the outlet port by the filter element, a method characterized by maintaining the pressure at the outlet side of the filter at a positive pressure above atmospheric pressure by controlling a feed rate per unit time of a feed pump installed in an upstream flow channel of the filter.

14. The method according to claim 13, wherein the filter does not comprise a spacer for securing a flow channel at the outlet side of the filter.

15. The method according to claim 13 or claim 14 wherein a filter of which the outlet side flexible housing has not been processed to provide irregularity as a spacer for securing a flow channel at the filter outlet side and/or a filter in which a tube is not inserted between the outlet side flexible housing and the sheet-like filter as a spacer for securing a flow channel at the filter outlet side are/is used.

16. The method according to claim 13, wherein the liquid to be filtered is blood.

17. The method according to claim 14, wherein the liquid to be filtered is blood.

18. The method according to claim 15, wherein the liquid to be filtered is blood.

19. The method according to claim 16, wherein the liquid to be filtered is blood.

20. The method according to claim 17, wherein the filter is used for removal of leukocytes.

21. The method according to claim 18, wherein the filter is used for removal of leukocytes.

22. In a filtering system for a liquid comprising a filter comprising a flexible housing having an inlet port and outlet port for the liquid, a sheet-like filter element for removing undesired components from the liquid, with the liquid inlet port and the outlet port separated from each other by the filter element, an upstream side flow channel connected to the filter inlet port, a filtered liquid recovery bag, a downstream side flow channel connecting the filter outlet port with the recovery bag, and a feed pump installed in the upstream side flow channel, a filtering system wherein the feed rate per unit time of a feed pump installed in an upstream flow channel of the filter can be controlled so that the pressure at the outlet side of the filter is maintained at a positive pressure above atmospheric pressure.

23. The system according to claim 22 comprising the filter without a spacer for securing a flow channel at the outlet side of the filter.

24. The system according to claim 22 or claim 23, wherein a filter of which the outlet side flexible housing has not been processed to provide irregularity as a spacer for securing a flow channel at the filter outlet port and/or a filter in which a tube is not inserted between the outlet side flexible housing and the sheet-like filter as a spacer for securing a flow channel at the filter outlet side are/is used.

25. The system according to claim 22, wherein the liquid to be filtered is blood.

26. The system according to claim 23, wherein the liquid to be filtered is blood.

27. The system according to claim 24, wherein the liquid to be filtered is blood.

28. The system according to claim 25, wherein the filter is used for removal of leukocytes.

29. The system according to claim 26, wherein the filter is used for removal of leukocytes.

30. The system according to claim 27, wherein the filter is used for removal of leukocytes.

31. A liquid filtering method using the system according to claim 22.

32. A liquid filtering method using the system according to claim 23.

33. A liquid filtering method using the system according to claim 24.

34. A liquid filtering method using the system according to claim 25.

35. A liquid filtering method using the system according to claim 26.

36. A liquid filtering method using the system according to claim 27.

37. A liquid filtering method using the system according to claim 28.

38. A liquid filtering method using the system according to claim 29.

39. A liquid filtering method using the system according to claim 30.

40. In a method of filtering blood or blood components using a filter comprising a flexible housing having an inlet port and outlet port, said inlet port being separated from the outlet port by a sheet-like filter element, said sheet-like filter element removing undesired elements from the blood, the method including:

connecting the inlet port to a source of blood or blood components;

connecting the outlet port to a container;

pumping the blood from the source to the filter by a pump station communicating with a blood or blood component flow channel;

adjusting at least one filtration parameter so that a pressure at an outlet side of the filter is above atmospheric pressure;

maintaining a pressure at the outlet side of the filter above atmospheric pressure throughout filtration by adjusting said at least one filtration parameter; and

collecting filtered blood or blood components in the container.

41. The method according to claim 40 wherein the pressure at the outlet side of the filter is maintained above atmospheric pressure by controlling a feed rate per unit time of a feed pump installed in an upstream flow channel of the filter.

42. The method according to claim 40 wherein the pressure at the outlet side of the filter is maintained above atmospheric pressure by restraining expansion of the inlet side flexible housing and the outlet side flexible housing by contacting an outer surface of each of said flexible housings with a separate restraining structure to restrain the outward expansion of said flexible housings under pressure applied during operation of a feed pump.

43. The method according to claim 40, wherein the filter does not comprise a spacer for securing a flow channel at the outlet side of the filter.

44. The method according to claim 40 wherein a filter of which the outlet side flexible housing has not been processed to provide irregularity as a spacer for securing a flow channel at the filter outlet side and/or a filter in which a tube is not inserted between the outlet side flexible housing and the sheet-like filter as a spacer for securing a flow channel at the filter outlet side are/is used.

45. The method according to claim 40, wherein the filter is used for removal of leukocytes.