Patent attributes
Hemodialysis systems are described. A hemodialysis system may include a dialysate flow path through which dialysate is passed from a dialysate reservoir, which includes a valved vent to atmosphere, to an ultrafilter. The dialysate flow path includes a pneumatically actuated diaphragm-based dialysate pump for pumping fluid from the dialysate reservoir to the ultrafilter. The hemodialysis system may include a controller for controlling pneumatic actuation pressure delivered to the dialysate pump and at least one valve connecting the dialysate reservoir vent to the atmosphere. The hemodialysis system may be configured to actuate the dialysate pump and the at least one valve to introduce air into the dialysate flow path and expel liquid from the dialysate flow path to a drain.