Abstract: A method of removing toxins from blood from a patient in need of such toxin removal includes: providing a countercurrent dialysis filter (20) having a blood compartment and a dialysate compartment separated from the blood compartment by a semi-permeable membrane; conveying blood from the patient through the blood compartment of a countercurrent filter (20) an back to the patient; and drawing dialysate from a reservoir (32) through the dialysate compartment of the countercurrent filter (20). At least one of the blood or dialysate experiences pulsatile flow. The steps are carried out such that blood toxins are drawn from the blood compartment through the semi-permeable membrane into the dialysate compartment.