HEMODIALYSIS SYSTEM HAVING A FLOW PATH WITH A CONTROLLED COMPLIANT VOLUME

• US 20160038666A1
• Filed: 10/19/2015
• Published: 02/11/2016
• Est. Priority Date: 08/02/2011
• Status: Active Grant

• Current Assignee: Mozarc Medical US LLC
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kelly, Thomas D., Lyu, SuPing, Pudil, Bryant J., Meyer, Thomas E.
• Granted Patent: US 10,722,636 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/3482 by filtrating the filtrate using another cross-flow filter, e.g. a membrane filter
• CPC Class Codes: A61M 2202/0021 removed from and reintroduced into the body, e.g. after treatment
• CPC Class Codes: A61M 2202/0413 Blood

Abstract

Systems and methods for the performance of kidney replacement therapy having or using a dialyzer, control components, sorbent cartridge and fluid reservoirs configured to be of a weight and size suitable to be worn or carried by an individual requiring treatment are disclosed. The system for performing kidney replacement therapy has a controlled compliance dialysis circuit, where a control pump controls the bi-directional movement of fluid across a dialysis membrane. The dialysis circuit and an extracorporeal circuit for circulating blood are in fluid communication through the dialysis membrane. The flux of fluid moving between the extracorporeal circuit and the dialysis circuit is modified by the rate at which the control pump is operating such that a rate of ultrafiltration and convective clearance can be controlled. The system provides for the monitoring of an inlet and outlet conductivity of the sorbent cartridge to provide a facility to quantify or monitor the removal of urea by the sorbent cartridge.

Claims

1. A system for performing dialysis, comprising:

a microbial filter having an inlet in fluid connection with a dialysis circuit having a sorbent cartridge for removing at least one impurity or waste species from a fluid; and

an outlet in fluid connection with a dialyzer having a dialysis membrane.

2. The system of claim 1, wherein the fluid is a dialysate and wherein the dialyzer comprises a blood inlet end for receiving blood, a blood outlet end for allowing blood out of the dialyzer, a dialysate inlet end for receiving dialysate and a dialysate outlet end for allowing dialysate out of the dialyzer, wherein the blood and the dialysate contact different sides of the dialysis membrane.

3. The system of claim 2, wherein the dialysis circuit has one or more conduits for conveying dialysate between the sorbent cartridge and the dialyzer, and a dialysate pump for conveying dialysate from the sorbent cartridge, to the dialyzer and back to the sorbent cartridge.

4. The system of claim 1, wherein the dialyzer is in fluid communication with an extracorporeal circuit comprising a conduit for receiving blood from a subject and a conduit for returning blood to the subject, and a blood pump for conveying blood from the subject, to the dialyzer and back to the subject.

5. The system of claim 1, wherein the microbial filter is positioned between the sorbent cartridge and the dialysate inlet end of the dialyzer on the dialysis circuit.

6. The system of claim 1, wherein at least one of a bicarbonate reservoir and an infusate reservoir is fluidly connected to the dialysis circuit, and wherein the microbial filter is positioned between the dialysate inlet end of the dialyzer and the bicarbonate reservoir, the infusate reservoir, or both the bicarbonate and the infusate reservoir.

7. The system of claim 1, wherein the dialysis circuit is a controlled compliance dialysis circuit.

8. The system of claim 4, further comprising an ultrafiltrate pump for moving fluid between the dialysis circuit and the extracorporeal circuit and an ultrafiltrate reservoir, wherein a flux of fluid moving between the extracorporeal circuit and the dialysis circuit is changed by the rate at which the ultrafiltrate pump is operating;

and wherein the ultrafiltrate reservoir stores fluid removed from the dialysis circuit by the ultrafiltrate pump or stores fluid that can be added to the dialysis circuit by the ultrafiltrate pump.

9. The system of claim 8, further comprising one or more controllers for controlling the rate of the ultrafiltrate pump, a rate of the blood pump, and a rate of a dialysate pump.

10. The system of claim 8, wherein the ultrafiltrate pump is a control pump.

11. The system of claim 1, wherein the fluid is water.

12. A system, comprising:

a hemofilter with a hemofiltration membrane, a blood inlet end for receiving blood, a blood outlet end for allowing blood out of the hemofilter, and an ultrafiltration outlet for allowing an ultrafiltrate out of the hemofilter;

an extracorporeal circuit having a conduit for receiving blood from a subject and a conduit for returning blood to the subject, and a blood pump for conveying blood from the subject, to the hemofilter and back to the subject;

a hemofiltration circuit having a sorbent cartridge for removing at least one impurity or waste species from the ultrafiltrate to generate a replacement fluid, wherein the ultrafiltrate enters an inlet end of the sorbent cartridge and a replacement fluid exits an outlet end of the sorbent cartridge, the hemofiltration circuit having one or more conduits and a filtrate pump for conveying the ultrafiltrate from the hemofilter to the sorbent cartridge and for infusing the replacement solution into the extracorporeal circuit; and

a microbial filter located in the hemofiltration circuit.

13. The system of claim 12, wherein the microbial filter is positioned in the hemofiltration circuit downstream of the sorbent cartridge.

14. The system of claim 12, wherein the hemofiltration circuit is a controlled compliant hemofiltration circuit.

15. The system of claim 12, further comprising at least one of a bicarbonate reservoir and an infusate reservoir fluidly connected to the hemofiltration circuit, and wherein the microbial filter is positioned between the extracorporeal circuit and the bicarbonate reservoir, the infusate reservoir, or both the bicarbonate and the infusate reservoir.

16. The system of claim 12, further comprising an ultrafiltrate pump, wherein the ultrafiltrate pump removes a portion of ultrafiltrate from the hemofiltration circuit, wherein the removed portion of the ultrafiltrate is not generated into the replacement fluid.

17. The system of claim 16, wherein the ultrafiltrate pump is a control pump.

18. A method comprising:

conveying blood from a subject through an extracorporeal circuit and a dialyzer and returning the blood to the subject;

conveying a dialysate through a dialysis circuit such that the dialysate moves from a sorbent cartridge, to the dialyzer and back to the sorbent cartridge, where at least one waste species diffuses from the blood to the dialysate through the dialysis membrane and the sorbent cartridge substantially removes at least one impurity or waste species from the dialysate; and

wherein the dialysate is conveyed through a microbial filter prior to entering the dialyzer.

19. The method of claim 18, wherein the dialysate is conveyed through the microbial filter after the dialysate is conveyed through the sorbent cartridge.

20. The method of claim 18, further comprising one or more of:

a) using a pump to add a cation solution to the dialysate; and

b) using a pump to add a bicarbonate solution to the dialysate;

wherein the cation solution or bicarbonate solution is added to the dialysate prior to conveying the dialysate through the microbial filter.

21. The method of claim 20, further comprising using an ultrafiltrate pump to move fluid between the dialysis circuit and the extracorporeal circuit, wherein a flux of fluid moving between the dialysis circuit and the extracorporeal circuit is changed by the rate at which the ultrafiltrate pump is operated.

22. The method of claim 21, wherein the ultrafiltrate pump is a control pump, and further comprising operating the ultrafiltrate pump to add fluid from a control reservoir to the dialysis circuit in an influx direction via a conduit or operating the ultrafiltrate pump to remove fluid from the dialysis circuit to the control reservoir in an efflux direction via the conduit, and intermittently switching the ultrafiltrate pump between the efflux direction to move fluid across the dialysis membrane from the extracorporeal circuit to the dialysis circuit and the influx direction to move fluid across the dialysis membrane from the dialysis circuit to the extracorporeal circuit.