PUMPING SYSTEMS FOR CASSETTE-BASED DIALYSIS

• US 20080033346A1
• Filed: 07/03/2007
• Published: 02/07/2008
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Lauman, Brian, Childers, Robert
• Granted Patent: US 8,206,338 B2
• Time in Patent Office: Days
• US Class Current: 604/29
• CPC Class Codes: A61M 1/1522 the interface being evacuated interfaces to enhance contact
• CPC Class Codes: A61M 1/154 with sensing means or components thereof
• CPC Class Codes: A61M 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/1561 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/1562 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/1565 Details of valves
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/281 Instillation other than by gravity
• CPC Class Codes: A61M 1/284 Continuous flow peritoneal dialysis [CFPD]
• CPC Class Codes: A61M 2205/122 using evacuated interfaces to enhance contact

Abstract

A peritoneal dialysis system includes a dialysis machine including a pump chamber and a pump actuator moveable within the pump chamber; a pumping cassette including a rigid portion defining a pump well and a flexible membrane covering the pump well; and wherein the dialysis machine is configured to be mated with the pumping cassette so as to hold a vacuum between the pump chamber and the flexible membrane, the vacuum operable to cause the flexible membrane to follow the pump actuator as the actuator is retracted from the pump well of the rigid portion, the pump actuator operable to cause the flexible membrane to move into the pump well as the actuator is moved into the pump well.

Claims

1. A peritoneal dialysis system comprising:

a dialysis machine including a pump chamber and a pump actuator moveable within the pump chamber;

a pumping cassette including a rigid portion defining a pump well and a flexible membrane covering the pump well; and

wherein the dialysis machine is configured to be mated with the pumping cassette so as to hold a vacuum between the pump chamber and the flexible membrane, the vacuum operable to cause the flexible membrane to follow the pump actuator as the actuator is retracted from the pump well of the rigid portion, the pump actuator operable to cause the flexible membrane to move into the pump well as the actuator is moved into the pump well.

2. The peritoneal dialysis system of claim 1, the pump actuator operable to draw dialysate into the pump well of the pumping cassette as the flexible membrane is retracted from the pump well.

3. The peritoneal dialysis system of claim 1, the pump actuator operable to push dialysate out of the pump well as the flexible membrane is moved into the pump well.

4. The peritoneal dialysis system of claim 1, wherein the pump actuator contacts the flexible membrane of the pumping cassette directly.

5. The peritoneal dialysis system of claim 1, wherein the pump actuator is configured to retract completely out of the pump well, the vacuum pulling the membrane away from the rigid portion of the pumping cassette.

6. The peritoneal dialysis system of claim 1, wherein the pump actuator includes a stepper motor.

7. The peritoneal dialysis system of claim 6, wherein the stepper motor is one of:

(i) coupled to a ball screw, the ball screw converting rotational motion of the stepper motor to a translational motion for the pump actuator; and

(ii) a linear stepper motor.

8. The peritoneal dialysis system of claim 1, wherein the pump actuator includes a shaft, the dialysis machine includes a shaft opening, and which includes a seal between the shaft and shaft opening, the seal aiding in holding the vacuum.

9. The peritoneal dialysis system of claim 1, wherein the pumping cassette is received non-vertically relative to the dialysis machine.

10. A peritoneal dialysis system comprising:

a dialysis machine including first and second pump chambers and first and second pump actuators moveable within the first and second pump chambers, respectively;

a pumping cassette including a rigid portion defining first and second pump wells and a flexible membrane covering the pump wells; and

the dialysis machine configured to be mated with the pumping cassette so as to hold a vacuum between the first pump chamber and the flexible membrane and between the second pump chamber and the flexible membrane, the vacuum operable to cause the flexible membrane to follow the first and second pump actuators as either actuator is moved in a fluid-filling direction, the first and second pump actuators operable to cause the flexible membrane to move into the first and second pump wells, respectively, of the rigid portion as the respective actuator is moved in a fluid-emptying direction.

11. The peritoneal dialysis system of claim 10, which is configured to move the first pump actuator in the fluid-filling direction while moving the second pump actuator in the fluid-emptying direction.

12. The peritoneal dialysis system of claim 10, wherein the first and second pump actuators are driven by first and second stepper motors, respectively.

13. The peritoneal dialysis system of claim 10, wherein the dialysis machine includes first and second actuator openings for the first and second pump actuators, respectively, the dialysis machine further including first and second seals positioned between the first and second actuator openings and the first and second pump actuators, respectively, the seals aiding in holding the vacuum at the first and second pump chambers.

14. The peritoneal dialysis system of claim 10, wherein the vacuum in the fluid-filling direction pulls the flexible membrane away from the rigid portion of the disposable cassette.

15. A peritoneal dialysis system comprising:

a dialysis machine including a vacuum chamber;

a pumping cassette including a rigid portion forming a pumping chamber and a flexible membrane covering the pumping chamber, the machine configured such that the vacuum chamber and the pumping chamber are mated when the disposable cassette is loaded into the dialysis machine;

a linear actuator configured to manually move the flexible membrane into the pump chamber of the pumping cassette; and

a vacuum formed in the vacuum chamber to pneumatically pull the flexible membrane to the linear actuator.

16. A peritoneal dialysis machine comprising:

a pumping cassette interface including first and second pump chambers and first and second shaft openings in fluid communication with the first and second pump chambers;

first and second pump actuators each including an actuator head and an actuator shaft, the first and second actuator heads positioned in the first and second pump chambers, respectively, the first and second actuator shafts positioned in the first and second shaft openings, respectively; and

first and second seals sealing the first and second actuator shafts to the first and second shaft openings so as to enable a vacuum to be present in the first and second pump chambers when a pumping cassette is mated to the pumping cassette interface so as to seal an opening of each of the first and second pump chambers.

17. The peritoneal dialysis machine of claim 16, the first and second actuator heads shaped and sized to fit tightly within the first and second pump chambers, respectively.

18. The peritoneal dialysis machine of claim 16, wherein at least one of the first and second actuator heads includes at least one groove configured to distribute the vacuum to the pumping cassette.

19. The peritoneal dialysis machine of claim 16, the first and second pump actuators including vacuum chambers configured to introduce the vacuum into the first and second pump chambers, respectively.

20. The peritoneal dialysis machine of claim 16, the vacuum introduced into the first and second pump chambers via a pathway disposed separately from the first and second pump actuators.