Abstract: A dialyzer composed of: first and second dialyzation chambers, and an intermediate chamber interposed between the first and second dialyzation chambers. Each dialyzation chamber has opposed first and second ends and contains a filter member that separates the chamber into a blood compartment and a dialysate compartment. Each of the compartments extends between first and second ends. Each of the chambers has a respective one of a blood inlet or outlet and a dialysate inlet or outlet arranged so that blood and dialysate flow in counter-current to one another in both chambers. The intermediate chamber is connected to form a dialysate-free blood flow passage between the blood compartments.

Abstract: An apparatus and method for use in blood dialysis. The apparatus includes: two dialyzers each containing a semipermeable membrane that divides the dialyzer into a blood compartment and a dialysate compartment; a blood compartment connecting line connecting the blood compartments of the dialyzers together in series; blood connecting lines for connecting the blood compartments to the vascular system of a patient; a dialysate compartment connecting unit connecting the dialysate compartments of the dialyzers together in series; and dialysate connecting lines for connecting the dialysate compartments to a dialysis machine. The dialysate compartment connecting unit includes an adjustable flow varying device for controllably setting the rate of the flow of dialysate through the connecting unit.