Peritoneal dialysis methods and apparatus

• US 8,096,969 B2
• Filed: 05/04/2010
• Issued: 01/17/2012
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California), U.S. Government Represented By The Department Of Veterans Affairs
• Original Assignee: National Aeronautics and Space Administration (Government of the United States of America), Regents of the University of California (University of California)
• Inventors: Roberts, Martin, Lee, David B. N.
• Primary Examiner(s): Mehta, Bhisma
• Application Number:
  US12/773,227
• Publication Number:
  US 20100217181A1
• Time in Patent Office: 623 Days
• Field of Search: 604/27, 604/29, 604/43, 604/45, 604/518
• US Class Current: 604/29
• CPC Class Codes: A61M 1/1686 by heat
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation

Abstract

A peritoneal-based (“bloodless”) artificial kidney processes peritoneal fluid without need for additional fluids (“waterless”). Fluid is separated into a protein-rich stream and a protein-free stream. The protein-rich stream is regenerated using a sorbent assembly, and its protein composition can be modified by removal of selected protein(s) (“dialysate-pheresis”). It is then reconstituted with additives and returned into the peritoneal cavity, thereby reducing protein-loss and providing oncotic-pressure for ultrafiltration. The protein-free stream is used to produce free water, and an alkaline or acid fluid for optimization of the composition of the regenerated stream. The unused protein-free stream can be used to “reverse flush” the separator to maintain its patency and the excess discarded for fluid-balance regulation. Compared to prior art, immobilization of urease allows more protein rich fluid to be regenerated and re-circulated into the peritoneal cavity for toxin removal and allows practicable development of portable and wearable artificial kidneys.

Claims

1. A peritoneal dialysis system, comprising:

a first fluid line that carries a fluid stream from a peritoneal cavity of a user;

a separator that separates the fluid stream into a relatively protein-rich stream and a relatively protein-free stream, wherein the relatively protein-rich stream averages at least 15% (by vol) of the fluid stream over at least some period of time; and

a processing line that includes a sorbent system that is configured to remove at least one toxin from at least some of the protein-rich stream to thereby allow production of a modified dialysate stream;

a second fluid line that introduces at least some of the modified dialysate stream into the peritoneal cavity; and

wherein at least some of the sorbent system includes an enzyme that is immobilized on a substrate with greater than Van der Waals forces.

2. The peritoneal dialysis system of claim 1, wherein the relatively protein-rich stream averages at least 40% (by vol) of the fluid stream from the peritoneal cavity over the at least some period of time.

3. The peritoneal dialysis system of claim 1, wherein the relatively protein-rich stream averages at least 90% (by vol) of the fluid stream from the peritoneal cavity over the at least some period of time.

4. The peritoneal dialysis system of claim 1, wherein the separator comprises a hollow fiber filter.

5. The peritoneal dialysis system of claim 1, further comprising a pump that at least temporarily affects a ratio of the relatively protein-rich stream to the relatively protein-free stream.

6. The peritoneal dialysis system of claim 1, wherein the sorbent system comprises a user-replaceable assembly having at least 100 gm of a sorbent.

7. The peritoneal dialysis system of claim 6, wherein the user-replaceable sorbent assembly has a dry weight of no more than 5 kg.

8. The peritoneal dialysis system of claim 6, wherein the user-replaceable sorbent assembly has a dry weight of no more than 2 kg.

9. The peritoneal dialysis system of claim 1, wherein the processing line includes a processor comprising at least one of a cation exchanger and an anion exchanger, which alters a concentration in at least a portion of the relatively protein-free stream of at least one of H⁺, OH⁻

, CO3<sup>−

−</sup>

and HCO3<sup>−

−</sup>

.

10. The peritoneal dialysis system of claim 1, wherein the processing line includes a gas extractor disposed to operate upon at least a portion of the relatively protein-rich stream.

11. The peritoneal dialysis system of claim 1, further comprising a monitor that measures a characteristic of the system.

12. The peritoneal dialysis system of claim 1, further comprising a sodium monitor and feedback loop that maintains an average sodium concentration of at least a portion of the relatively protein-rich stream within a desired range over a period of at least 1 hour.

13. The peritoneal dialysis system of claim 1, further comprising a pH monitor and feedback loop that maintains an average pH of at least a portion of the relatively protein-rich stream within a desired range over a period of at least 1 hour.

14. The peritoneal dialysis system of claim 1, further comprising an ammonia detector and feedback loop that triggers an action when an ammonia concentration in at least a portion of the relatively protein-rich stream is greater than a predetermined value.

15. The peritoneal dialysis system of claim 1, further comprising a glucose addition module, and at least one enrichment module that collectively adds at least two of potassium, calcium, and magnesium to at least a portion of the relatively protein-rich stream.

16. The peritoneal dialysis system of claim 1, further comprising a unit that targets removal of a specific protein from at least a portion of the relatively protein-rich stream.

17. The peritoneal dialysis system of claim 1, further comprising an ultrasonic vibrator that operates upon at least a portion of the relatively protein-rich stream and that is configured to facilitate solvation of additives.

18. The peritoneal dialysis system of claim 1, wherein the second fluid line is operable concurrently with the first fluid line.

19. The peritoneal dialysis system of claim 1, wherein the processing line, excluding a user-replaceable sorbent cartridge, has a dry weight of no more than 5 kg.

20. The peritoneal dialysis system of claim 1, wherein the processing line excluding a user-replaceable sorbent assembly has a dry weight of no more than 2 kg.

21. The peritoneal dialysis system of claim 1, wherein the processing line includes a gas removal unit disposed to operate upon at least a portion of the relatively protein-rich stream.

22. The peritoneal dialysis system of claim 1, further comprising a power source sufficient to operate the processing line continuously for at least 7 hours.