US Patent 7909795 Dialysis system having disposable cassette and interface therefore

A medical fluid flow control system includes an interface including a first pump area, the first pump area of the interface including a pneumatic actuator port and a gasket seal port; 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 a flexible sheet of a pumping cassette.