Extracorporeal fluid circuit

• US 20070106198A1
• Filed: 10/21/2005
• Published: 05/10/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Inventors: Jensen, Lynn, Schlaeper, Christian, Reihanifam, Mohsen, Crnkovich, Martin, Folden, Thomas
• Granted Patent: US 7,871,391 B2
• Time in Patent Office: Days
• US Class Current: 604/6.140
• CPC Class Codes: A61M 1/36222 Details related to the interface between cassette and machine
• 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 1/362262 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 1/3643 Priming, rinsing before or after use
• CPC Class Codes: A61M 2205/123 with incorporated reservoirs
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A61M 2205/7563 with means preventing clogging of filters

Abstract

A chamber is described for use in an extracorporeal fluid system. The chamber has a bottom entry port and a bottom exit port. A microporous filter at the top of the chamber allows air in the fluid to vent from the chamber. In use, the chamber is filled with saline. Blood is then introduced into the chamber. A layer of saline is above a layer of blood in the chamber. The saline stagnates as the blood flows through the chamber. The saline keeps the blood from contacting the filter and depositing protein on the filter.

Claims

1. An apparatus for removing air from a bodily liquid in extracorporeal circuitry, comprising:

a vertical chamber having a bottom region and a top region and a pair of fluid entry and exit ports at or near the bottom region; and

a microporous filter at or near the top region, whereby liquid is passed through the vertical chamber from the entry port to the exit port so as to fill the vertical chamber with the liquid while removing air from the chamber.

2. The apparatus of claim 1, wherein the microporous filter includes a hydrophobic material.

3. The apparatus of claim 1, wherein the fluid entry and exit ports are in a bottom surface of the vertical chamber.

4. The apparatus of claim 1, wherein the microporous filter forms at least a portion of a top surface of the vertical chamber.

5. The apparatus of claim 1, further comprising a dam between the entry port and the exit port.

6. The apparatus of claim 1, wherein the vertical chamber has a height sufficient to maintain an interface between a first liquid in the vertical chamber and a second liquid in the vertical chamber when the first and second liquids are miscible and the second liquid is flowing through the vertical chamber.

7. The apparatus of claim 1, wherein the bottom region of the vertical chamber is wider than the top region.

8. The apparatus of claim 1, further comprising a clot filter positioned in the bottom region of the chamber, the clot filter positioned so that the liquid passes through the clot filter prior to passing through the exit port.

9. The apparatus of claim 1, wherein the microporous filter fits within a housing connected at the top region of the chamber.

10. The apparatus of claim 1, wherein the bottom surface is sufficiently wide to accommodate an entry tube and an exit tube wherein the entry tube is connected to the entry port and the exit tube is connected to the exit port.

11. A method of removing air from a bodily liquid in extracorporeal circuitry, comprising:

passing a first liquid through an entry port into a bottom region of a vertical chamber, filling the chamber so that substantially no air remains in the chamber; and

passing a second liquid through the entry port into the bottom region of the vertical chamber, thereby forcing a portion of the first liquid out of an exit port from the bottom region of the vertical chamber and forming a liquid-liquid interface between the first and second liquids, whereby any gas bubbles contained in the second liquid is forced out of a top region of the vertical chamber through a microporous filter.

12. The method of claim 11, wherein the second liquid is miscible with the first liquid and the vertical chamber is long enough to prevent the first and second liquids from mixing because the first liquid stagnates.

13. The method of claim 11, further comprising passing the second liquid through an exit port after any gas in the second liquid has escaped, thereby passing a substantially air-free second liquid through the exit port for delivery to a patient.

14. The method of claim 11, wherein passing a first liquid through an entry port includes passing a blood-compatible component through the entry port.

15. The method of claim 11, wherein passing a first liquid through an entry port includes passing saline through the entry port.

16. The method of claim 11, wherein passing a second liquid through an entry port includes passing blood through the entry port.

17. The method of claim 11, further comprising:

forcing the second liquid over the dam after passing the second liquid through the entry port; and

passing the second liquid out an exit port after forcing the second liquid over the dam.

18. The method of claim 11, further comprising:

passing the second liquid through a clot filter; and

passing the second liquid through an exit port after passing the second liquid through the clot filter.

19. An integrated fluid circuit component adapted to removably seat in a bodily liquid purification machine, comprising:

a rigid body having a substantially flat main portion and a plurality of recessed portions extending from the flat main portion; and

a flexible backing covering at least one of the of recessed portions;

wherein a first recessed portion forms a vertical chamber, the vertical chamber having a microporous filter at or near a top region, a second recessed portion forms a first channel that is in fluid communication with a bottom region of the vertical chamber and a third recessed portion forms a second channel in fluid communication with the bottom region of the vertical chamber.

20. The component of claim 19, wherein the flexible backing is sealed to the flat main portion of the rigid body, at least partially enclosing the recessed portions.

21. The component of claim 19, wherein the plurality of recessed portions includes a fourth recessed portion overlapping the first channel, the fourth recessed portion being wider than the first channel.

22. The component of claim 21, wherein the plurality of recessed portions includes a fifth recessed portion that forms a third channel, the third channel extending to an edge of the rigid body and not directly contacting the first, second, third or fourth recessed portions.

23. The component of claim 22, wherein the plurality of recessed portions include a sixth recessed portion overlapping the third channel, the sixth recessed portion being wider than the third channel.

24. The component of claim 22, wherein the third channel is in fluid communication with a first tube coupled to the rigid body.

25. The component of claim 22, wherein the plurality of recessed portions includes a seventh recesses portion that forms a fourth channel, the fourth channel extending to at least one edge of the rigid body and not directly contacting the first, second, third, fourth, fifth or sixth recessed portions.

26. The component of claim 25, wherein the plurality of recessed portions includes an eighth recessed portion overlapping the fourth channel, the eighth recessed portion being wider than the fourth channel.

27. The component of claim 19, wherein the first and second channels extend to an edge of the rigid body.

28. The component of claim 27, further comprising tubes coupled with the rigid body, the tubes being in fluid communication with the first and second channels.

29. The component of claim 19, wherein the vertical chamber further comprises a clot filter adjacent to the second channel.

30. The component of claim 19, wherein the microporous filter includes a hydrophobic material.

31. The component of claim 19, wherein the vertical chamber has a height sufficient to maintain an interface between a first liquid in the vertical chamber and a second liquid in the vertical chamber when the first and second liquids are miscible and the first liquid is substantially stagnant as the second liquid flows through the vertical chamber.

32. The component of claim 19, further comprising one or more injection sites, wherein the injection sites are formed on the rigid body and the one or more injection sites overlap a recessed portion.

33. The component of claim 32, wherein the one or more injection sites include a neoprene gasket.

34. The component of claim 19, further comprising a rigid backing, wherein the rigid backing backs at least the first and second channels and the rigid backing includes at least one opening in which the flexible backing is located.

35. An integrated fluid circuit component for use in a bodily liquid purification machine, comprising:

a rigid body having a substantially flat main portion and a plurality of recessed portions extending from the flat main portion;

a flexible backing covering at least one of the plurality of recessed portions; and

a plurality of flexible tubes, wherein;

a first recessed portion forms a vertical chamber, the vertical chamber having a hydrophobic microporous filter at or near a top region, the vertical chamber having a sufficient height to maintain an interface between a first liquid in the vertical chamber and a second liquid in the vertical chamber when the first and second liquids are miscible and the first liquid is substantially stagnant as the second liquid flows through the chamber,

a second recessed portion forms a first channel that is in fluid communication with a bottom region of the first recessed portion,

a third recessed portion forms a second channel in fluid communication with the bottom region of the first recessed portion,

the second and third recessed portions extend to an edge of the rigid body and are each in fluid communication with a tube of the plurality of flexible tubes;

a fourth recessed portion overlaps a section of the third recessed portion and is wider than the third recessed portion; and

a fifth recessed portion forms a third channel and extends from an edge of the rigid body, the fifth recessed portion is in fluid communication with a tube of the plurality of flexible tubes.