Cassette system for peritoneal dialysis machine

• US 20070112297A1
• Filed: 08/31/2006
• Published: 05/17/2007
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius SE & Co. KGaA)
• Inventors: Klatte, Stephan, Hedmann, Frank, Folden, Thomas, Plahey, Kulwinder
• Granted Patent: US 7,935,074 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 1/1524 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 1/16 with membranes
• 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 2205/122 using evacuated interfaces to enhance contact
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches

Abstract

A portable peritoneal dialysis apparatus having a side-hinged, inclined door for enclosing a disposable cassette that seals tightly shut using air pressure which imposes a safety interlock, a cassette with its inlet/outlet tube exclusively along the lower edge so that the connected lines can hang straight, a circumferential channel defined in the cassette, and a pneumatic system for sealing the membranes of both the pump chamber diaphragms and the pressure sensor diaphragms in the cassette to the respective mating pistons and pressure sensors in the cycler. In addition a system for draining patient line fluid to an empty solution bag is disclosed.

Claims

1. An apparatus for pumping fluids between a peritoneal dialysis machine and a patient in order to perform peritoneal dialysis on the patient, comprising:

a disposable cassette for routing PD solution,

a cassette compartment defined by a deck lying in a plane inclined from the vertical by 10 to 35 degrees having openings for valve actuators and piston heads and a door hinged from the side so as to close in parallel over the deck and enclose the cassette within the compartment.

2. The apparatus of claim 1 wherein said angle of inclination is about 20 to 25 degrees.

3. The apparatus of claim 2 wherein said angle of inclination is about 22 degrees.

4. The apparatus of claim 1, wherein the cassette has inlet/outlet connections along the bottom of the cassette, the compartment accommodating the connection of vertically hanging tubes to the inlet/outlet connections on the cassette.

5. The apparatus of claim 4, wherein all of the inlet/outlet connections are in a line along the bottom edge of the cassette so that together they make bend substantially greater than 90 degrees when sitting on a flat surface.

6. An apparatus for pumping fluids between a peritoneal dialysis machine and a patient in order to perform peritoneal dialysis on the patient, comprising:

a cassette compartment defined by a door and a cassette deck,

a PD solution cassette fitting between the door and the cassette deck, and

an inflatable pad carried by the door which forces the cassette into sealing engagement with the cassette deck when the door is closed and the pad is inflated.

7. The apparatus of claim 6 further comprising a door latch mechanism which is locked by the force of the inflatable pad tending to push the door away from the cassette deck.

8. An apparatus for pumping fluids between a peritoneal dialysis machine and a patient in order to perform peritoneal dialysis on the patient, comprising:

a disposable cassette defining channels, valves and pump chambers for routing PD solution to and from inlet/outlet connections on the cassette,

a cassette compartment with a cassette deck for sealingly engaging the cassette,

the cassette having a diaphragm covering at least one pump chamber facing the deck,

the deck having a reciprocating piston head mounted for reciprocation in a cylindrical chamber, an annular space surrounding the piston head between the chamber walls,

a pneumatic system for drawing a vacuum in the cylindrical chamber, the vacuum drawing the diaphragm tight against the piston head so that the diaphragm retracts with the piston head.

9. The apparatus of claim 8 further comprising a pressure sensor in the deck, the cassette having a sensor diaphragm that mates with the pressure sensor positioned to sense pressure in a PD solution line, the sensor being surrounded by a vacuum chamber, the pneumatic system drawing a sufficient vacuum in the pressure sensor vacuum chamber to seal the sensor diaphragm against the pressure sensor.

10. A disposable cassette for a PD machine, comprising

a molded plastic panel having a circumferential fluid channel defined along the perimeter of the panel

11. The cassette of claim 10, further including at least one pump chamber, said channel circumnavigating all of the pump chambers in the cassette.

12. A method of operating a PD machine, comprising

draining spent PD solution from the patient to an empty solution bag that had been filled with PD solution earlier that was used to infuse the same patient.

13. The method of claim 12, wherein the step of draining to an empty solution bag is carried out by using a multichannel cassette with a preexisting connection to the solution bag and patient.