Patent ID: 8740837

Claim:
A peritoneal dialysis method comprising: enabling the mating of a disposable pumping cassette with a peritoneal dialysis machine; moving first and second piston heads towards the disposable pumping cassette to contact and move first and second respective portions of a flexible membrane of the pumping cassette into a rigid portion of the pumping cassette to push (i) fresh dialysate out of the pumping cassette through a patient line towards a patient or (ii) spent dialysate to a drain line towards a drain; and applying from a pneumatic pressure source (a) a first vacuum to mate the first portion of the flexible membrane to the first piston head and (b) a second vacuum to mate the second portion of the flexible membrane to the second piston head to cause the first and second portions of the flexible membrane to respectively follow the first and second piston heads as either piston head is moved away from the pumping cassette to pull (i) fresh dialysate from a fresh dialysate supply line or (ii) spent dialysate from the patient line to fill a respective first or second pump chamber of the pumping cassette.