A portable peritoneal dialysis apparatus having (1) a hinged door for enclosing a disposable cassette that seals tightly shut using air pressure (2) accurate pressure sensing of pressures applied to the patient through an enclosure in the disposable cassette (3) two pumps that can operate separately or in tandem actuated by two separate stepper motors and (4) a touch screen user interface where indicia of the operating mode is always visible along with indicia for the other possible operating modes and the mode can be changed by touching one of these indicia.
