Personal hemodialysis system

1. A dialysis method comprising:

applying a pneumatic closing pressure to a first valve chamber of a dialysis machine which comprises (i) a flexible membrane, (ii) a flexible diaphragm, (iii) a compliance chamber including at least one of the flexible membrane or the flexible diaphragm and (iv) a second valve chamber; and

arranging the compliance chamber to flex and absorb energy from the pneumatic closing pressure so as to tend to prevent the pneumatic closing pressure from opening an existing closure of the second valve chamber.

2. The dialysis method of claim 1 , wherein applying the pneumatic closing pressure to the first valve chamber includes applying pressure to the flexible membrane, the flexible membrane additionally covering a rigid portion of the compliance chamber.

3. The dialysis method of claim 2 , which includes flexing the compliance chamber by flexing the flexible membrane.

4. The dialysis method of claim 2 , which includes flexing the compliance chamber by flexing the flexible diaphragm, the flexible diaphragm operating with the rigid portion of the compliance chamber.

5. The dialysis method of claim 4 , which includes locating the diaphragm on an opposing side of the rigid portion from the flexible membrane.

6. The dialysis method of claim 1 , wherein arranging the compliance chamber includes locating the compliance chamber between the first and second valve chambers.

7. The dialysis method of claim 1 , wherein the first and second valve chambers are located in a disposable cassette operable with the dialysis machine.

8. The dialysis method of claim 1 , wherein the first valve chamber is located upstream of the second valve chamber.

9. The dialysis method of claim 1 , which includes applying a vacuum to the compliance chamber to absorb the energy from the pneumatic closing pressure applied to close the first valve chamber.

10. A dialysis method comprising:

applying a pneumatic closing pressure to a first valve chamber of a dialysis system, which comprises (i) a compliance chamber including at least one of a flexible membrane or a flexible diaphragm and (ii) a second valve chamber;

arranging the compliance chamber to flex and absorb a backpressure due to a pneumatic closing pressure applied to an existing closure of a second valve chamber to help ensure the pneumatic closing pressure applied to the first valve chamber will close the first valve chamber.

11. The dialysis method of claim 10 , which includes

operating a disposable cassette of the dialysis system, the disposable cassette including the first and second valve chambers, with a dialysis instrument of the dialysis system, the dialysis instrument including a pump actuator and first and second valve actuators;

operating the first and second valve chambers of the disposable cassette with the first and second valve actuators of the dialysis instrument, respectively; and

operating a pump portion of the disposable cassette with the pump actuator of the dialysis instrument.

12. The dialysis method of claim 10 , wherein the pneumatic closing pressure applied to the second valve chamber is substantially the same as the pneumatic closing pressure applied to the first valve chamber.

13. The dialysis method of claim 10 , wherein flexing the compliance chamber prevents the backpressure from existing around an outside of a port of the first valve chamber.

14. A dialysis method comprising:

applying a pneumatic closing pressure to a first valve chamber of a dialysis system, which comprises (i) a compliance chamber comprising at least one of a flexible membrane or a flexible diaphragm and (ii) a second valve chamber; and

arranging the compliance chamber to flex and absorb a first backpressure due to the pneumatic closing pressure applied to the first valve chamber to help ensure the pneumatic closing pressure will close the first valve chamber against a second backpressure from an existing closure of the second valve chamber.

15. The dialysis method of claim 14 , wherein flexing the compliance chamber tends to prevent the pneumatic closing pressure applied to the first valve chamber from opening the closed second valve chamber.

16. The dialysis method of claim 14 , wherein flexing the compliance chamber includes applying a vacuum to the compliance chamber to negate the first backpressure.

17. A dialysis method comprising:

applying a vacuum to a flexible membrane or flexible diaphragm of a compliance chamber of a dialysis system to aid at least one of: (i) closing a first valve chamber of a disposable cassette of the dialysis system at a time when a second valve chamber of the disposable cassette is already closed, or (ii) maintaining an existing closure of the second valve chamber when the first valve chamber is closed; and

allowing the first and second valve chambers to communicate fluidly with the compliance chamber.

18. The dialysis method of claim 17 , which includes flexing the flexible membrane of the disposable cassette to close the first and second valve chambers.

19. A dialysis method comprising:

applying a pneumatic closing pressure to a flexible membrane of a dialysis system to close a first valve chamber of a disposable cassette of the dialysis system;

absorbing energy from the pneumatic closing pressure via a compliance chamber of the disposable cassette formed at least in part by a flexible diaphragm; and

locating the flexible membrane and the flexible diaphragm on opposite sides of the disposable cassette.

20. The dialysis method of claim 19 , which includes communicating the first valve chamber fluidly with the compliance chamber.