PUMPING SYSTEMS FOR CASSETTE-BASED DIALYSIS

• US 20120259276A1
• Filed: 06/20/2012
• Published: 10/11/2012
• Est. Priority Date: 07/19/2002
• 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: Childers, Robert W., Lauman, Brian
• Granted Patent: US 8,679,054 B2
• Time in Patent Office: Days
• US Class Current: 604/28
• 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 dialysis machine includes: a hardware unit including at least one pump actuator, at least one valve actuator and a cassette interface, the cassette interface including: (i) a plate that abuts the cassette; (ii) at least one pump aperture defined by the plate; (iii) at least one pump head moveable out of and retractable into the at least one pump aperture to operate a pumping portion of the cassette; (iv) at least one valve aperture defined by the plate; (v) at least one valve apparatus moveable out of and retractable into the at least one valve aperture to operate a valve portion of the cassette; (vi) at least one sensor aperture defined by the plate; and (vii) at least one sensor located in the least one sensor aperture, the at least one sensor operable with a sensor portion of the cassette.

Claims

1. A peritoneal dialysis method comprising:

applying a vacuum from a vacuum chamber to a portion of a flexible membrane of a dialysis fluid carrying pumping cassette aligned with the vacuum chamber;

turning a stepper motor shaft a controlled amount to correspondingly move a piston head and the portion of the flexible membrane into the pumping cassette, so as to push fresh dialysis fluid out of the disposable cassette through a patient line connected to a patient connector or spent dialysis fluid out through a drain line; and

turning the stepper motor shaft in an opposite direction a controlled amount to correspondingly retract the piston head from the portion of the flexible membrane of the pumping cassette membrane, the vacuum causing the flexible membrane to follow the piston head as the piston head is retracted, so as to draw fresh dialysis fluid into the pumping cassette through a fill line connected to a dialysate source or spent dialysis fluid into the pumping cassette through the patient line.

2. The peritoneal dialysis method of claim 1, which includes directly contacting the portion of the flexible membrane with the piston head when moving the piston head into the pumping cassette.

3. The peritoneal dialysis method of claim 1, which includes retracting the piston head completely from a rigid portion of the pumping cassette.

4. The peritoneal dialysis method of claim 1, which includes connecting the drain line to a drain before moving the piston head towards the pumping cassette.

5. The peritoneal dialysis method of claim 1, which includes mechanically communicating the stepper motor with the piston head.

6. The peritoneal dialysis method of claim 5, which includes rotatably sealing the piston shaft to an opening in the vacuum chamber.

7. The peritoneal dialysis method of claim 1, which includes connecting the patient line to a patient transfer set before moving the piston head into the pumping cassette.

8. The peritoneal dialysis method of claim 1, which includes coupling the pumping cassette to the peritoneal dialysis machine at a non-vertical angle.

9. A peritoneal dialysis method comprising:

enabling the mating of a disposable pumping cassette with a peritoneal dialysis machine;

moving first and second pistons heads towards the disposable pumping cassette to contact and move first and second respective portions of a flexible membrane of the pumping cassette into a rigid portion of the pumping cassette to push (i) fresh dialysate out of the pumping cassette through a patient line towards a patient or (ii) spent dialysate to a drain line towards a drain; and

applying a first vacuum to mate the first portion of the flexible membrane to the first piston head and a second vacuum to mate the second portion of the flexible membrane to the second piston head to cause the first and second portions of the flexible membrane to respectively follow the first and second piston heads as either piston head is moved away from the pumping cassette to pull (i) fresh dialysate from a fresh dialysate supply line or (ii) spent dialysate from the patient line to fill a respective first or second pump chamber of the pumping cassette.

10. The peritoneal dialysis method of claim 9, which includes moving the first piston head towards the pumping cassette to push fresh dialysate to the patient line or spent dialysate to the drain line while moving the second piston head away from the pumping cassette to pull fresh dialysate from the dialysate supply line or spent dialysate from the patient line, respectively.

11. The peritoneal dialysis method of claim 10, which in a second stroke includes moving the first piston head away from the pumping cassette to pull fresh dialsyate from the dialysate supply line or spent dialysate from the patient line, while moving the second piston head towards the pumping cassette to push fresh dialysate to the patient line or spent dialsyate to the drain line, respectively.

12. The peritoneal dialysis method of claim 9, which includes prompting a fluid connection of the patient line to an indwelling patient catheter after mating the pumping cassette to the peritoneal dialysis machine.

13. The peritoneal dialysis method of claim 12, which includes moving the first and second piston heads and applying the first and second vacuums to prime the pumping cassette with fresh dialysate prior to the prompting of the fluid connection.

14. A peritoneal dialysis method comprising:

enabling a disposable cassette to be aligned so that (i) a soft side of the disposable cassette faces towards a vacuum chamber and a piston head of a peritoneal dialysis machine and (ii) a dialysis fluid supply line, a patient line and a drain line extend from a hard part of the disposable cassette outside of the peritoneal dialysis machine to a respective dialysis fluid supply container, a patient and a drain;

positioning the piston head relative to the vacuum chamber;

applying a vacuum through the vacuum chamber to pull the soft side of the disposable cassette to the piston head to at least partially mate the soft side of the disposable cassette with the piston head;

pushing fresh dialysis fluid from the disposable cassette through the patient line or spent dialysis fluid from the disposable cassette through the drain line as the piston head and the soft side of the disposable cassette are extended at least partially into the hard part of the disposable cassette; and

drawing fresh dialysis fluid through the supply line or spent dialysis fluid through the patient line into the disposable cassette as the piston head retracts from the hard part of the disposable cassette while using the vacuum to hold the soft side of the disposable cassette in at least partial contact with the piston head.

15. The peritoneal dialysis method of claim 14, which includes retracting the piston head completely out of the hard part of the disposable cassette and causing the soft side of the disposable cassette to be moved away from the hard side of the disposable cassette.

16. The peritoneal dialysis method of claim 14, which includes extending the piston head at least partially into the hard part of the disposable cassette a present distance using a stepper motor.

17. The peritoneal dialysis method of claim 14, which includes enabling the disposable cassette to be aligned with the peritoneal dialysis machine at a non-vertical angle.

18. The peritoneal dialysis method of claim 14, which includes conforming the shape and size of the piston head to a shape and size of a pump chamber portion of the hard part of the disposable cassette.

19. The peritoneal dialysis method of claim 14, which includes positioning the piston head relative to the vacuum chamber to allow a shaft held mechanically with the piston head to move back and forth sealingly within the vacuum chamber.

20. The peritoneal dialysis method of claim 14, which includes configuring the disposable cassette alignment so that multiple dialysis fluid supply lines can extend from a same edge of the disposable cassette.