A portable hemodialysis system is provided suitable for in home use. The hemodialysis system includes a disposable cartridge and a reused dialysis machine. The disposable cartridge includes a dialyzer, and a dialysate flow path and a blood flow path which flow in opposing directions through the dialyzer. In addition, the disposable cartridge possesses pump actuators (but not pump motors) for pumping dialysate and blood through their respective flow paths. The pump actuators having non-deformable components including a housing having a central cavity forming an internal sidewall, a rotor eccentrically positioned within the cavity having radially aligned slots at the rotors periphery, and vanes slideably positioned in the slots to slide in and out of the slots so as to seal with the cavitys internal sidewall creating vane chambers that pump blood or dialysate.