Medical fluid pump

• US 6,814,547 B2
• Filed: 05/24/2002
• Issued: 11/09/2004
• Est. Priority Date: 05/24/2002
• Status: Expired due to Fees

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Busby, Don, Childers, Robert
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US10/155,754
• Publication Number:
  US 20030217962A1
• Time in Patent Office: 900 Days
• Field of Search: 417/53, 417/374, 417/375, 417/394, 417/413.1, 92/80, 92/86, 921/01, 210/252, 210/258, 210/321.71, 604/28, 604/29, 604/151, 604/152, 604/153, 604/154, 604/155
• US Class Current: 417/53
• CPC Class Codes: A61M 1/153 the cassette being adapted for heating or cooling the treating fluid, e.g. the dialysate or the treating gas
• 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 1/1565 Details of valves
• CPC Class Codes: A61M 1/159 specially adapted for peritoneal dialysis
• CPC Class Codes: A61M 1/166 Heating for sterilisation A61M1/1686
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/288 Priming priming in extracorporeal blood circuits A61M1/3643
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/122 using evacuated interfaces to enhance contact
• CPC Class Codes: A61M 2205/127 with provisions for heating or cooling
• CPC Class Codes: A61M 2205/33 Controlling, regulating or measuring
• CPC Class Codes: A61M 2205/3337 Controlling, regulating pressure or flow by means of a valve by-passing a pump
• CPC Class Codes: A61M 2205/3344 Measuring or controlling pressure at the body treatment site
• CPC Class Codes: A61M 2205/35 Communication
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 5/445 the media being heated in the reservoir, e.g. warming bloodbags
• CPC Class Codes: F04B 43/02 : having plate-like flexible members, e.g. diaphragms F04B43/14 takes precedence
• CPC Class Codes: F04B 45/04 : having plate-like flexible members, e.g. diaphragms F04B45/10 takes precedence
• CPC Class Codes: H05B 1/025 : For medical applications
• CPC Class Codes: Y10S 706/90 : Fuzzy logic
• CPC Class Codes: Y10T 137/87161 : With common valve operator

Abstract

A method, system and apparatus for performing peritoneal dialysis are provided. To this end, in part, a pump for a dialysis system is provided. The pump includes a first chamber wall including a first aperture, a second chamber wall including a second aperture, a piston, at least a portion of which can move through the second aperture, the piston including a third aperture, and first and second membranes disposed between the first and second chambers walls. A vacuum can be applied through the first aperture to pull the first membrane towards the first chamber wall and can be applied through the third aperture to pull the second membrane towards the piston. The piston can thereafter move the second membrane.

Claims

1. A pump for a dialysis system connected to at least one vacuum source, the pump comprising:

a first chamber wall including a first aperture;

a second chamber wall including a second aperture;

a piston, at least a portion of which can move through the second aperture, the piston including a third aperture;

first and second membranes disposed between the first and second chamber walls, wherein a vacuum can be applied from the at least one vacuum source through the first aperture to pull the first membrane towards the first chamber wall and can be applied from the at least one vacuum source through the third aperture to pull the second membrane towards the piston, wherein the piston can thereafter move the second membrane; and

a dialysis fluid opening enabling dialysis fluid to be pulled in between the first and second membranes upon movement of the piston.

2. The pump of claim 1, wherein the first and second chamber walls include opposing surfaces of a dialysis hardware unit.

3. The pump of claim 1, wherein the piston includes a piston head and the second membrane can be pulled by the vacuum towards the piston head.

4. The pump of claim 1, wherein the piston is driven by a stepper motor.

5. The pump of claim 4, wherein the stepper motor is a linear stepper motor.

6. The pump of claim 1, which includes a diaphragm disposed between the first and second chamber walls, the diaphragm moveable by the piston.

7. The pump of claim 6, wherein the second membrane moves toward the diaphragm and the piston when the vacuum is applied.

8. The pump of claim 6, wherein the diaphragm is constructed from an elastomer.

9. The pump of claim 6, wherein the diaphragm is constructed from an elastomer and includes a fabric reinforcement.

10. The pump of claim 1, wherein the first and second chamber walls form a shell shape with substantially aligned edges and the first and second membranes are sealed together substantially in cooperation with the aligned edges.

11. The pump of claim 1, which includes a first vacuum chamber that communicates with the first aperture and a second vacuum chamber that communicates with the third aperture.

12. A pump connected to at least one vacuum source for use in a system for providing dialysis treatment, the pump comprising:

a first chamber wall;

a second chamber wall, the second chamber wall defining an aperture;

first and second fluid receiving membranes disposed between the first and second chamber walls, the at least one vacuum source operable to apply a vacuum between the membrane and the walls;

a piston, at least a portion of which moves through the aperture, the piston including a piston head having an external shape substantially similar to a mating internal shape of the first chamber wall, the piston in operation contacting one of the membranes; and

a dialysis fluid opening enabling dialysis fluid to be pulled in between the first and second membranes upon movement of the piston.

13. The pump of claim 12, wherein the first and second membranes can be pulled apart by a vacuum applied through an aperture defined by the first chamber wall and through an aperture defined by the piston.

14. The pump of claim 12, which includes a diaphragm disposed partially between the piston head and the second chamber wall.

15. The pump of claim 14, wherein the diaphragm is elastomeric and can follow a movement of the piston head.

16. A method of operating a pump for use in a medical treatment comprising the steps of:

pneumatically pulling on an outer surface of each of two fluid receiving membranes to pull medical fluid in between the membranes;

mechanically pushing a first one of the membranes; and

communicating a fluid lumen with a space between the membranes so that medical fluid is forced out of the space between the membranes to the lumen when the first membrane is mechanically pushed.

17. The method of claim 16, which includes the step of providing a diaphragm that moves with a member that pushes the first membrane.

18. The method of claim 17, which includes the step of pneumatically pulling the first membrane towards the diaphragm.

19. The method of claim 17, wherein pneumatically pulling on each of the outer surfaces of each of the two membranes further includes pneumatically pulling the diaphragm towards the member.

20. The method of claim 17, which includes the step of sealing the membranes and the diaphragm between first and second chamber walls.

21. The method of claim 16, wherein mechanically pushing the first membrane includes advancing a stepper motor a number of steps.

22. The method of claim 16, which includes the step of applying positive pressure to the outer surface of at least one of the membranes to expel air between the membranes.

23. The method of claim 22, which includes the step of positioning the member to a desired location before applying the positive pressure.

27. The method of claim 16, wherein pulling medical fluid in between the membranes includes pneumatically pulling on an outer surface of each of the two membranes and mechanically moving a member away from the membranes.

24. An automated dialysis system comprising:

a disposable dialysis unit placed into a housing;

at least one vacuum source;

a pump for pumping dialysate, the pump cooperating with the dialysis unit and including;

a first chamber wall including a first aperture;

a second chamber wall including a second aperture;

a piston, at least a portion of which moves through the second aperture, the piston including a third aperture; and

first and second membranes disposed between the first and second chamber walls, wherein a vacuum can be applied from the at least one vacuum source through the first aperture to pull the first membrane towards the first chamber wall and can be applied from the at least one vacuum source through the third aperture to pull the second membrane towards the piston, wherein the piston can thereafter move the second membrane; and

a dialysis fluid opening enabling dialysis fluid to be pulled in between the first and second membranes upon movement of the piston.

25. The system of claim 24, wherein the vacuum source is located separate from at least one of the disposable dialysis unit and the pump.

26. The system of claim 24, wherein the first and second membranes are provided by the disposable dialysis unit.