Dialysis system having disposable cassette and interface therefore

1. A medical fluid flow control system comprising:

an interface including a first pump area, the first pump area of the interface including a pneumatic actuator port and a gasket seal port;

a pumping cassette defining a pump chamber and including a flexible sheet, a pumping portion of the flexible sheet covering the pump chamber; and

a membrane gasket including a second pump area for mating with the first pump area, the second pump area including a blind section which covers the pneumatic actuator port when the gasket is mated with the interface, the second pump area further including an aperture, the aperture sized and positioned to seal around the gasket seal port, allowing a negative pressure to be applied through the gasket seal port to the flexible sheet of the pumping cassette.

2. The medical flow control system of claim 1 , which is configured to mate the pumping portion of the flexible sheet with the blind section of the second pump area, the blind section and the pumping portion of the flexible sheet flexing together to pull dialysis fluid in and push dialysis fluid out of the pump chamber of the pumping cassette.

3. The medical fluid flow control system of claim 1 , the negative pressure applied through the gasket seal port sealing the pumping portion of the flexible sheet to the second pump area.

4. The medical fluid flow control system of claim 1 , wherein the pump chamber of the cassette has a shape at least substantially similar to a shape of the second pump area, which is at least substantially similar to a shape of the first pump area.

5. The medical fluid flow control system of claim 1 , wherein the first pump area includes at least one of a well and a raised ridge.

6. The medical fluid flow control system of claim 5 , wherein at least one of: (i) the pneumatic actuator port is an aperture through the well, (ii) the gasket seal port resides adjacent to the well, and (iii) the blind section of the pump area of the gasket is sized to seal around the raised ridge of the first pump area.

7. The medical fluid flow control system of claim 1 , wherein the gasket seal port projects from a base of the interface so as to be able to extend at least partially through the aperture in the membrane gasket.

8. The medical fluid flow control system of claim 1 , which includes an additional pump area of the interface, which mates with an additional pump area of the gasket.

9. The medical fluid flow control system of claim 1 , which includes a pressure sensor monitoring the negative pressure, and a logic implementor operable with an output of the pressure sensor to determine if a leak associated with one of the following has occurred (i) the second pump area and (ii) a portion of the flexible sheet of the pumping cassette mated with the second pump area.

10. The medical fluid flow control system of claim 9 , which includes a fluid sensor, the logic implementor further configured to determine (i) that the leak is in the membrane gasket if the fluid sensor does not detect a fluid or (ii) that the leak is in the flexible sheet of the pumping cassette if the fluid sensor detects a fluid.

11. A medical fluid flow control system comprising:

an interface including a first valve area, the first valve area including a pneumatic actuator port and a gasket seal port;

a pumping cassette defining a valve chamber and including a flexible sheet, a valve portion of the flexible sheet covering the valve chamber; and

a membrane gasket including a second valve area for mating with the first valve area, the second valve area including a blind section which covers the pneumatic actuator port when the gasket is mated with the interface, the second valve area further including an aperture, the aperture sized and positioned to seal around the gasket seal port, allowing a negative pressure to be applied through the gasket seal port to the flexible sheet of the pumping cassette.

12. The medical flow control system of claim 11 , which is configured to mate the valve portion of the flexible sheet with the blind section of the second valve area, the blind section and the valve portion of the flexible sheet flexing together to open and close a fluid pathway of the pumping cassette.

13. The medical fluid flow control system of claim 11 , the negative pressure applied through the gasket seal port sealing the valve portion of the flexible sheet to the second valve area.

14. The medical fluid flow control system of claim 11 , wherein the valve chamber of the cassette has a shape at least substantially similar to a shape of the second valve area, which is at least substantially similar to a shape of the first valve area.

15. The medical fluid flow control system of claim 11 , wherein the first valve area includes a raised seat, the pneumatic actuator port being an aperture through the raised seat.

16. The medical fluid flow control system of claim 15 , wherein the gasket seal port resides adjacent to the raised seat.

17. The medical fluid flow control system of claim 15 , wherein the blind section of the second valve area is sized to seal around the raised seat of the first valve area.

18. The medical fluid flow control system of claim 11 , which includes an additional valve area of the interface, which mates with an additional valve area of the gasket.

19. The medical fluid flow control system of claim 11 , which includes a pressure sensor monitoring the negative pressure, and a logic implementor operable with an output of the pressure sensor to determine if a leak associated with one of the following has occurred (i) the second valve area and (ii) a portion of the flexible sheet of the pumping cassette mated with the second valve area.

20. The medical fluid flow control system of claim 19 , which includes a fluid sensor, the logic implementor further configured to determine (i) that the leak is in the membrane gasket if the fluid sensor does not detect a fluid or (ii) that the leak is in the flexible sheet of the pumping cassette if the fluid sensor detects a fluid.