Carbon Dioxide Gas Removal From a Fluid Circuit of a Dialysis Device

• US 20090282980A1
• Filed: 01/16/2009
• Published: 11/19/2009
• Est. Priority Date: 01/18/2008
• 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: Beizai, Mesoud, Gura, Victor, Ezon, Carlos Jacobo
• Granted Patent: US 8,034,161 B2
• Time in Patent Office: Days
• US Class Current: 96/6
• CPC Class Codes: A61M 1/1658 Degasification
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: B01D 19/0031 by filtration

Abstract

The present invention is directed to degassing devices for dialysate circuits. One embodiment has a first housing and a second housing positioned within the first housing in an annular relationship. A second embodiment comprises a dialysate regeneration system with urease, a dialyzer, and a housing with an external wall, where the external wall is exposed to atmosphere and comprises a material that passes gas but does not pass liquid and where the housing is positioned between the urease and dialyzer.

Claims

1. A degassing device comprising:

a. a first housing having an inlet, a first length and an inner wall defining a first inner chamber;

b. a second housing positioned within said first inner chamber in an annular relation to the first housing wherein the second housing has an outer wall, an outlet, a second length and an inner wall defining a second inner chamber, wherein the second length is less than the first length, and wherein a space between the first length and second length defines a gap;

c. a flowpath through said degassing device wherein said flowpath is defined by the inlet, the gap, and the outlet; and

d. a hydrophobic membrane positioned proximate to said gap.

2. The degassing device of claim 1 wherein the gap is between about 0.02 inches and 0.1 inches.

3. The degassing device of claim 1 wherein a space between said inner wall of the first housing and outer wall of the second housing is between about 0.04 to 0.24 inches.

4. The degassing device of claim 1 wherein said degassing device is capable of removing substantially all gas from dialysate at flow rates between 20 ml/min and 450 ml/min.

5. The degassing device of claim 1 wherein said second housing comprises a filter.

6. The degassing device of claim 5 wherein the filter is approximately 0.1 to 0.4 inches thick.

7. The degassing device of claim 1 wherein the hydrophobic membrane is positioned a distance from said second housing wherein said distance is equal to the gap.

8. The degassing device of claim 1 wherein the inlet and outlet are positioned on a same side of said degassing device.

9. The degassing device of claim 1 wherein fluid having gas flows into the first inner chamber through said inlet, flows through said gap, flows past the hydrophobic membrane, flows into said second inner chamber, and flows through said outlet, wherein gas passes through the hydrophobic membrane and wherein liquid does not pass through said hydrophobic membrane.

10. A dialysate circuit comprising a dialysate regeneration system with urease, a dialyzer, and the degassing device of claim 1.

11. The dialysate circuit of claim wherein said degassing device is positioned between the urease and the dialyzer.

12. A dialysate circuit comprising:

a. a dialysate regeneration system comprising urease;

b. a housing comprising an external wall, wherein the external wall is exposed to atmosphere and wherein the external wall comprises a material that passes gas but does not pass liquid; and

c. a dialyzer, wherein said housing is positioned between the urease and dialyzer.

13. The dialysate circuit of claim 12 wherein the housing comprises at least one of a tube, a section of tubing, or a coil of tubing.

14. The dialysate circuit of claim 12 wherein the housing comprises a membrane that is between 0.5 feet to 16 feet long.

15. The dialysate circuit of claim 12 wherein the housing comprises a membrane that has an outer diameter of about 0.1 to 0.45 inches.

16. The dialysate circuit of claim 12 wherein the housing comprises a membrane that has an inner diameter of about 0.1 to 0.4 inches.

17. The dialysate circuit of claim 12 wherein the housing removes substantially all gas from the dialysate at flow rates from about 20 ml/min to 200 ml/min.

18. The dialysate circuit of claim 12 wherein the housing removes substantially all gas from the dialysate at internal pressures at or below 10 psi.

19. The dialysate circuit of claim 12 wherein the dialysate regeneration system comprises charcoal and wherein said housing is positioned between the charcoal and dialyzer.