Fluid, circuits, systems, and processes for extracorporeal blood processing

• US 7,419,597 B2
• Filed: 04/03/2007
• Issued: 09/02/2008
• Est. Priority Date: 07/12/2001
• Status: Expired due to Term

• Current Assignee: Nxstage Medical Incorporated (Fresenius Medical Care AG)
• Original Assignee: Nxstage Medical Incorporated (Fresenius Medical Care AG)
• Inventors: Brugger, James M., Treu, Dennis M., Burbank, Jeffrey H.
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US11/695,739
• Publication Number:
  US 20070185430A1
• Time in Patent Office: 518 Days
• Field of Search: 210/644, 210/645, 210/646, 210/650, 210/793, 210/798, 210/805, 210/180, 210/188, 210/194, 210/195.1, 210/195.2, 210/257.1, 210/257.2, 210/258, 210/321.6, 210/321.69, 210/321.71, 210/416.1, 210/436, 210/472, 604/5.04, 604/6.09, 604/6.11
• US Class Current: 210/646
• CPC Class Codes: A61M 1/1692 Detection of blood traces in dialysate
• CPC Class Codes: A61M 1/3437 downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3441 Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 1/3444 in which the collected ultra-filtrate expels an equal volume of substitution fluid from a reservoir
• CPC Class Codes: A61M 1/3462 Circuits for the preparation thereof
• CPC Class Codes: A61M 1/3465 using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3643 Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 Mode of operation
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/705 Testing of filters for leaks blood in dialysate A61M1/1692
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration

Abstract

A method for renal replacement therapy includes priming a fluid circuit and recirculating the sterile fluid during priming to permit gas to float out of the sterile fluid into a fluid reservoir. The fluid is preferably either warmed during circulation or vibrated to promote the removal of gas.

Claims

1. A method for performing renal replacement therapy with a treatment device that employs a fluid circuit with liquid and blood fluid circuits separated by a membrane, the membrane having a pore size effective to block the passage of pyrogenic material, the method comprising:

connecting a source of electrolytically-balanced fluid to the liquid fluid circuit;

ensuring sterility of the electrolytically-balanced fluid by passing the same through the membrane to produce sterile fluid and storing the sterile fluid in a reservoir;

warming and maintaining a temperature of the sterile fluid until a treatment time;

recirculating the sterile fluid through the reservoir to permit gas to be purged from the sterile fluid by permitting gas to be floated out of the sterile fluid in the reservoir and prime a portion of the fluid circuit;

priming a further portion of the fluid circuit.

2. A method as in claim 1, wherein the priming a further portion is executed after the recirculating.

3. A method as in claim 1, further comprising conveying blood from a patient through the blood fluid circuit during a treatment cycle and removing waste from the blood from the blood circuit through the membrane to the liquid fluid circuit.

4. A method as in claim 1, further comprising using the sterile fluid from reservoir in the process of performing a blood waste removing process on a patient.

5. A method as in claim 1, wherein the ensuring sterility includes ensuring a rate of endotoxins below a predetermined level by filtering with a membrane with a pore size effective to limit endotoxins.

6. A method as in claim 5, wherein the predetermined level is 3 EUs/ml. or less.

7. A method as in claim 1, further comprising vibrating the reservoir to aid in the removal of gas.

8. A method as in claim 1 wherein the passing the electrolytically-balanced fluid includes operating a blood pump in a first direction, the method further including conveying blood through the fluid circuit at the treatment time, the conveying blood including operating the blood pump in a second direction opposite the first direction.

9. A method for performing renal replacement therapy with a treatment device that employs a fluid circuit with liquid and blood fluid circuits separated by a membrane, the method comprising:

connecting a source of electrolytically-balanced fluid to the liquid fluid circuit;

passing the electrolytically-balanced fluid through the membrane and storing the resulting sterile fluid in a reservoir;

warming the sterile fluid prior to a treatment time; and

recirculating the sterile fluid through the reservoir to permit gas to be purged from the sterile fluid and prime at least a portion of the fluid by permitting gas to be floated out of the sterile fluid in the reservoir circuit.

10. A method as in claim 9, further comprising priming a further portion of the fluid circuit after recirculating the sterile fluid through the reservoir.

11. A method as in claim 9, further comprising conveying blood from a patient through the blood fluid circuit during a treatment cycle and removing waste from the blood from the blood circuit through the membrane to the liquid fluid circuit.

12. A method as in claim 9, further comprising using the sterile fluid from reservoir in the process of performing a blood waste removing process on a patient.

13. A method as in claim 9, wherein the passing the electrolytically-balanced fluid through the membrane includes providing a rate of endotoxins below a predetermined level by filtering with a membrane with a pore size effective to limit endotoxins.

14. A method as in claim 13, wherein the predetermined level is 3 EUs/ml. or less.

15. A method as in claim 9, further comprising vibrating the reservoir to aid in the removal of gas.

16. A method as in claim 9 wherein the passing the electrolytically-balanced fluid includes operating a blood pump in a first direction, the method further including conveying blood through the fluid circuit at the treatment time, the conveying blood including operating the blood pump in a second direction opposite the first direction.