Peritoneal dialysis methods and apparatus

• US 8,187,250 B2
• Filed: 01/30/2007
• Issued: 05/29/2012
• 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: Regents of the University of California (University of California)
• Inventors: Roberts, Martin, Lee, David B. N.
• Primary Examiner(s): Mehta, Bhisma
• Application Number:
  US11/700,690
• Publication Number:
  US 20070179431A1
• Time in Patent Office: 1,946 Days
• Field of Search: 604/29, 604/502, 604/518
• US Class Current: 604/500
• 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 method of processing a substantially blood-free fluid derived from a peritoneal cavity of a person, comprising:

separating the substantially blood-free fluid into a relatively protein-rich fluid and a relatively protein-free fluid such that a stream of the relatively protein-rich fluid averages at least 15% (by vol) of a stream of the substantially blood-free fluid over at least some period of time;

processing the relatively protein-rich fluid with a sorbent having an at least substantially immobilized urease to produce a purified regenerated fluid, wherein the urease is immobilized with greater than Van der Waals forces;

depositing at least some of the purified regenerated fluid back into the peritoneal cavity; and

wherein at least 80% of the substantially blood-free fluid is re-circulated into the peritoneal cavity as the purified regenerated fluid over a period of 8 hours.

2. The method of claim 1, wherein the step of depositing occurs concurrently with the step of separating.

3. The method of claim 1, wherein the step of depositing occurs intermittently with the step of separating.

4. The method of claim 1, further comprising using a filter to filter out the relatively protein-free fluid from the relatively protein-rich fluid.

5. The method of claim 1, further comprising controlling at least two of:

(a) a cation in the purified fluid;

(b) an anion in the purified fluid;

(c) a gas; and

(d) a glucose level in the purified fluid.

6. The method of claim 1, further comprising re-circulating to the person at least 80% of the substantially blood-free fluid as the purified fluid over a period of 4 hours.

7. The method of claim 1, further comprising re-circulating at least 90% of the substantially blood-free fluid as the purified fluid over a period of 8 hours.

8. The method of claim 1, further comprising re-circulating the substantially blood-free fluid as the purified fluid at a rate sufficient to provide at least 20 liters of purified fluid over a 10 hour period.

9. The method of claim 1, further comprising re-circulating the substantially blood-free fluid as the purified fluid at a rate sufficient to provide at least 48 liters of purified fluid over a 24 hour period.

10. The method of claim 1, wherein the step of processing occurs at least 40 hours during a period of seven consecutive days.

11. The method of claim 1, wherein the step of processing occurs at least 126 hours during a period of seven consecutive days.

12. The method of claim 1, further comprising embodying the steps of separating and processing in a device, and the person wearing the device.

13. The method of claim 1, further comprising processing at least a portion of the relatively protein-free fluid through at least one of a reverse osmosis unit and an ion-exchanger, and then adding a resulting product into a stream containing the relatively protein-rich fluid.

14. A method of processing a substantially blood-free fluid derived from a peritoneal cavity of a person, comprising:

separating the substantially blood-free fluid into a relatively protein-rich fluid and a relatively protein-free fluid such that a stream of the relatively protein-rich fluid averages at least 15% (by vol) of a stream of the substantially blood-free fluid over at least some period of time;

processing the relatively protein-rich fluid with a sorbent having an at least substantially immobilized urease to produce a purified regenerated fluid, wherein the urease is immobilized with greater than Van der Waals forces;

depositing at least some of the purified regenerated fluid back into the peritoneal cavity;

wherein at least 90% of the substantially blood-free fluid is re-circulated into the peritoneal cavity as the purified regenerated fluid over a period of 8 hours; and

further comprising a step of processing at least a portion of the relatively protein-free fluid through at least one of a reverse osmosis unit and an ion-exchanger, and then adding a resulting product into a stream containing the relatively protein-rich fluid.