A peritoneal dialysis machine including a membrane pump and a touch screen display that includes a mode-indicating portion and an operation-descriptive portion, the mode-indicating portion having a plurality of touch sensitive indicia each indicating one of a plurality of modes in which the machine can operate, the display being used to keep a patient continually informed of which one mode of at least three operating modes the machine is operating in, as the operation-descriptive portion changes to display details of a specific operation being carried out within the one mode, the indicia for each of the three operating modes always being visible to the patient while the machine is operating, the operating mode being selected by the patient touching one of the indicia on the screen.