Liquid pumping mechanisms for peritoneal dialysis systems employing fluid pressure

• US 5,634,896 A
• Filed: 04/11/1995
• Issued: 06/03/1997
• Est. Priority Date: 03/03/1993
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Miller, Bradley D., Spencer, Geoffrey P., Kamen, Dean, Vincent, Douglas E., Bryant, Robert J., Lanigan, Richard, Bouchard, Clement D.
• Primary Examiner(s): Millin, Vincent
• Assistant Examiner(s): Tao, Ellen
• Application Number:
  US08/420,196
• Time in Patent Office: 784 Days
• Field of Search: 604/19, 604/27-31, 604/34, 604/66, 604/67, 128/DIG. 13, 128/DIG. 12, 137/15, 137/613
• US Class Current: 604/29
• CPC Class Codes: A61M 1/152 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/1524 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• 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 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/281 Instillation other than by gravity
• CPC Class Codes: A61M 1/288 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: Y10S 128/12 Pressure infusion
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

Pumping mechanisms for performing peritoneal dialysis and the like employ a pumping mechanism comprising a diaphragm that operate in response to applied fluid pressure. Flexible tubing is attached to the pumping mechanism for carrying liquid to and from the patient'"'"'s peritoneal cavity. An actuating station for pumping mechanism receives the pumping mechanism and attached tubing. A pressure transfer element conveys fluid pressure to the diaphragm for moving liquid through the cassette. An occluder element contacts and crimps closed the tubing attached to the cassette. A first reservoir inflates with positive fluid pressure for contacting the pressure transfer element to hold it in operative contact against the diaphragm. A second reservoir inflates with positive fluid pressure for contacting the occluding element to hold it away from crimping contact with the tubing. At least one of the first and second reservoirs also transports fluid pressure to the pressure transfer element for conveyance to the diaphragm.

Claims

1. A pumping apparatus for a peritoneal dialysis system comprising:

a pumping mechanism comprising a diaphragm and a pump chamber, wherein the diaphragm overlies the pump chamber,

means for establishing liquid flow communication between the pumping mechanism and the peritoneal dialysis system, and

an actuator for contacting and actuating the pumping mechanism comprising

pressure transfer means operative, when in contact against the diaphragm of the pump chamber, for conveying fluid pressure to the diaphragm for moving liquid through the pump chamber,

reservoir means that inflates in response to the introduction of positive fluid pressure for contacting the pressure transfer means to hold it in operative contact against the diaphragm,

conduit means for transporting positive fluid pressure from a positive fluid pressure source to the reservoir means, and

pressure regulator means communicating with the reservoir means and the pressure transfer means for maintaining positive fluid pressure in the reservoir means above a predetermined amount to maintain operative contact between the pressure transfer means and the diaphragm while transporting positive fluid pressure from the reservoir means to the pressure transfer means for conveyance to the diaphragm.

2. An apparatus according to claim 1,

wherein the pressure transfer means conveys both positive fluid pressure from the reservoir means and negative fluid pressure from a negative fluid pressure source to the diaphragm for moving liquid through the pump chamber.

3. An apparatus according to claim 1,

wherein the pressure transfer means conveys pneumatic pressure.

4. An apparatus according to claim 1,

and further including a carrier for moving the pressure transfer means between an at rest position away from the diaphragm and an operating position in operative contact against the diaphragm, and

and wherein the reservoir means, during inflation, moves the carrier from the at rest position toward the operative position.

5. An apparatus according to claim 4,

and further including means for biasing the carrier toward the at rest position.

6. A pumping apparatus for a peritoneal dialysis system, comprising:

a liquid distribution cassette comprising a pump chamber and an overlying diaphragm,

flexible tubing means attached to the cassette for establishing liquid flow communication between the pump chamber and at least one component of the peritoneal dialysis system,

an actuating station for the cassette including

support means for receiving the cassette and the attached tubing means,

pressure transfer means operative when the cassette and tubing means are received in the support means for contact against the diaphragm and for conveying fluid pressure to the diaphragm for moving liquid in the flexible tubing means through the pump chamber,

flow shutoff means for the attached tubing means including

occluding means operative when the cassette and tubing means are received in the support means for movement between a normally biased flow disabled position contacting and crimping closed the tubing means and a flow enabled position out of contact with the tubing means,

occluder bladder means that inflates in response to the introduction of a predetermined amount of positive fluid pressure for contacting the occluding means and holding the occluding means in its flow enabled position as long as the predetermined positive pressure is maintained in the occluder bladder means, and

occlusion control means operative in a first control condition for conveying positive fluid pressure from a source to the occluder bladder means to maintain the predetermined positive pressure, the occlusion control means being further operative in a second control condition for venting the positive pressure in the occluder bladder means to cause the occluder means to move into its normally biased flow disabled position

wherein the actuating station includes

reservoir means that inflates in response to the introduction of a predetermined amount of positive pneumatic pressure for contacting the pressure transfer means and holding the pressure transfer means in operative contact against the diaphragm, and

pressure regulator means communicating with the reservoir means for maintaining the predetermined amount of positive pressure in the reservoir means to maintain the operative contact between the pressure transfer means and the diaphragm.

7. A system for performing peritoneal dialysis, comprising:

a liquid distribution cassette comprising a diaphragm pump for moving liquid through the liquid distribution cassette in response to the application of fluid pressure to the diaphragm pump,

flexible tubing attached to the liquid distribution cassette for establishing liquid flow communication between the diaphragm pump and the patient'"'"'s peritoneal cavity,

a source of fluid pressure for actuation of the diaphragm pump, and

an actuating station for receiving the liquid distribution cassette and the flexible tubing and for actuating the diaphragm pump with fluid pressure received from the fluid pressure source including

a chamber for receiving the liquid distribution cassette and the attached flexible tubing,

pressure transfer means in the chamber operative, when the liquid distribution cassette and the flexible tubing are received in the chamber, for conveying fluid pressure from the fluid pressure source to the diaphragm pump for moving liquid through the liquid distribution cassette,

occluding means operative when the liquid distribution cassette and the flexible tubing are received in the chamber for contacting and crimping closed the flexible tubing attached to the cassette,

first reservoir means in the chamber that inflates in response to the introduction of fluid pressure from the fluid pressure source for contacting the pressure transfer means to hold it in operative contact against the diaphragm pump, and

second reservoir means in the chamber that inflates in response to the introduction of fluid pressure from the fluid pressure source for contacting the occluding means to hold it away from crimping contact with the flexible tubing.

8. A system according to claim 7,

and further including means communicating with at least one of the first and second reservoir means for transporting fluid pressure from the at least one reservoir means to the pressure transfer means for conveyance to the diaphragm.

9. A system according to claim 7,

and further including venting means connected to the second reservoir means, said venting means being operative in response to a predetermined operating condition for venting the second reservoir means to permit movement of the occluding means into crimping contact against the tubing.

10. A system according to claim 9,

wherein the flexible tubing comprises a plurality of tubes attached to the cassette, and

wherein, upon venting of the second reservoir means, the occluding means moves into simultaneous crimping contact with all the tubes.

11. A system according to claim 7,

wherein the pressure source is a source of pneumatic pressure.

12. A system for performing peritoneal dialysis by pumping liquid dialysate to and from a patient'"'"'s peritoneal cavity, comprising:

a cassette including a body having a side edge and means defining a plurality of liquid distribution pathways in the body, each of the liquid distribution pathways including a port, the ports extending in an adjacently spaced relationship from the one side edge of the cassette,

a plurality of flexible tubes, one attached to each of the cassette ports, for establishing flow communication among the plurality of liquid distribution pathways and the patient'"'"'s peritoneal cavity, and

an operating station for the cassette including

a chamber for holding the cassette,

occluding means within the chamber selectively operable for contacting and crimping closed flexible tubes, and

means for holding the flexible tubes in alignment with the occluding means so that, upon operation, the occluding means simultaneously contacts and crimps closed all flexible tubes attached to the cassette,

wherein the occluding means includes

an occluder movable into crimping contact with the flexible tubes,

bladder means that inflates in response to the introduction of fluid pressure from a source for holding the occluder away from the crimping contact, and

means operative in response to a predetermined operating condition for venting the bladder means and for moving the occluder into the crimping contact.