A system includes a dialyzer having a blood side and a dialysate side, a first extracorporeal circuit including one or more first fluid connectors for connecting the blood side of the dialyzer to the vascular system of a kidney patient, a second extracorporeal circuit including one or more second fluid connectors for connecting the dialysate side of the dialyzer to the vascular system of a healthy animal, a first pump in fluid communication with at least one of the first and second extracorporeal circuits, and a driver mechanically coupled to the first pump, where the driver is configured to drive the first pump using energy from an energy source.
