Peritoneal dialysis machine

• US 8,900,174 B2
• Filed: 12/05/2011
• Issued: 12/02/2014
• Est. Priority Date: 10/28/2003
• 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.
• Primary Examiner(s): Wiest, Philip R
• Application Number:
  US13/373,909
• Publication Number:
  US 20120083729A1
• Time in Patent Office: 1,093 Days
• Field of Search: 604/4.01, 604/5.01, 604 61- 616, 604 27- 29, 604151-155, 210/252, 210/258, 210/321.71, 417/53, 417/374, 417/375
• US Class Current: 604/6.11
• CPC Class Codes: A61B 5/02042 Determining blood loss or bleeding, e.g. during a surgical procedure
• CPC Class Codes: A61M 1/1522 the interface being evacuated interfaces to enhance contact
• 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 1/154 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 1/1565 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 1/284 Continuous flow peritoneal dialysis [CFPD]
• CPC Class Codes: A61M 1/288 Priming priming in extracorporeal blood circuits A61M1/3643
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3641 Pressure isolators
• CPC Class Codes: A61M 1/3643 Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 Mode of operation
• CPC Class Codes: A61M 1/3652 using gas, e.g. air
• CPC Class Codes: A61M 2205/122 using evacuated interfaces to enhance contact
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/70 : with testing or calibration facilities
• CPC Class Codes: G01L 7/00 : Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements G01L11/004 takes precedence; transmitting or indicating the displacement of mechanical pressure-sensitive elements by electric , e.g., photoelectric or magnetic means G01L9/00; measuring differences of two or more pressure values G01L13/00; measuring two or more pressure values simultaneously G01L15/00
• CPC Class Codes: G01M 3/04 : by detecting the presence of fluid at the leakage point

Abstract

A method for operating a dialysis cassette including a flexible membrane that covers a pump chamber includes applying a vacuum about a piston head and sucking the flexible membrane of the dialysis cassette onto the piston head; mechanically retracting the piston head along with the vacuum applied membrane away from the dialysis cassette to draw fluid into the pump chamber; mechanically extending the piston head and the flexible membrane into the pump chamber to expel fluid from the pump chamber through a flow path; and directly sensing a pressure of the fluid flowing through the flow path at a location of the dialysis cassette adjacent to the pump chamber.

Claims

1. A method for operating a dialysis cassette including a flexible membrane that covers a pump chamber, the method comprising:

applying a vacuum about a piston head and sucking the flexible membrane of the dialysis cassette onto the piston head;

mechanically retracting the piston head along with the vacuum applied membrane away from the dialysis cassette to draw fluid into the pump chamber;

mechanically extending the piston head and the flexible membrane into the pump chamber to expel fluid from the pump chamber through a flow path; and

directly sensing a pressure of the fluid flowing through the flow path at a location of the dialysis cassette adjacent to the pump chamber.

2. The dialysis cassette operating method of claim 1, which further includes at least one of (i) applying the vacuum when retracting the piston head away from the dialysis cassette to draw fluid into the pump chamber or (ii) applying the vacuum when extending the membrane into the pump chamber to expel fluid from the pump chamber through the flow path.

3. The dialysis cassette operating method of claim 1, which further includes directly sensing the pressure of the fluid flowing through the flow path at a location of the dialysis cassette between the pump chamber and a valve actuation position of the flow path.

4. The dialysis cassette operating method of claim 1, wherein applying the vacuum about the piston head includes pulling the vacuum through the piston head or adjacent to the piston head.

5. The dialysis cassette operating method of claim 1, wherein applying the vacuum about the piston head includes pulling the vacuum between the flexible membrane and a wall through which the piston head moves to reach the pump chamber.

6. The dialysis cassette operating method of claim 1, wherein directly sensing the pressure of the fluid flowing through the flow path includes contacting the flexible membrane with a pressure sensor.

7. A method for operating a dialysis cassette including a flexible membrane that covers a pump chamber, the method comprising:

applying a vacuum about a piston head and sucking the flexible membrane of the dialysis cassette onto the piston head;

mechanically retracting the piston head along with the vacuum applied membrane away from the dialysis cassette to draw fluid into the pump chamber;

mechanically extending the piston head and the flexible membrane into the pump chamber to expel fluid from the pump chamber through a flow path;

directly sensing a pressure of the fluid flowing through the flow path at a location of the dialysis cassette adjacent to the pump chamber; and

determining that a line occlusion has occurred if the sensed pressure increases when mechanically extending the piston head and the membrane into the pump chamber.

8. The dialysis cassette operating method of claim 7, which includes determining if the line occlusion occurs during a priming sequence.

9. The dialysis cassette operating method of claim 7, wherein the flow path is in fluid communication with a patient line.

10. A method for operating a dialysis cassette including a flexible membrane that covers a pump chamber, the method comprising:

applying a vacuum about a piston head and sucking the flexible membrane of the dialysis cassette onto the piston head;

mechanically retracting the piston head along with the vacuum applied membrane away from the dialysis cassette to draw fluid into the pump chamber;

mechanically extending the piston head and the flexible membrane into the pump chamber to expel fluid from the pump chamber through a flow path;

directly sensing a pressure of the fluid flowing through the flow path at a location of the dialysis cassette adjacent to the pump chamber; and

determining that a line occlusion has occurred if the sensed pressure fails to meet an expected pressure drop when mechanically extending the piston head and the membrane into the pump chamber.

11. The dialysis cassette operating method of claim 10, which includes predetermining the expected pressure drop.

12. The dialysis cassette operating method of claim 10, which includes determining if the line occlusion occurs during a priming sequence.

13. The dialysis cassette operating method of claim 10, wherein the flow path is in fluid communication with a patient line.

14. A method for operating a dialysis cassette including a flexible membrane that covers a pump chamber, the method comprising:

applying a vacuum about a piston head and sucking the flexible membrane of the dialysis cassette onto the piston head;

mechanically retracting the piston head along with the vacuum applied membrane away from the dialysis cassette to draw fluid into the pump chamber;

mechanically extending the piston head and the flexible membrane into the pump chamber to expel fluid from the pump chamber through a flow path; and

determining that a leak in the dialysis cassette has occurred if it is detected that the piston head has moved when the piston head is expected to remain stationary.

15. The dialysis cassette operating method of claim 14, which includes causing the piston head to apply a force to the flexible membrane of the dialysis cassette to look for the leak.