Hemodiafiltration apparatus

Hemodiafiltration apparatus comprising a dialyzer (12) which is divided by a membrane into two chambers, the first chamber being connected into a dialysis solution path (22) and the second chamber into an extracorporeal blood path (104, 106) of a patient, the dialysis solution path comprising a supply line (32, 34, 42, 52, 22) which extends from a means for preparing dialysis solution (26) up to the dialyzer (12) and through which a first balance chamber (30) is connected, and a discharge line (24) which extends from the dialyzer (12) to a drain (72) and through which a second balance chamber (70) is connected, a circulation pump (68) for conveying dialysis solution in the dialysis solution path, a connecting line (74) which branches from the supply line (22) between the first balance chamber (30) and the dialyzer (12) and which is connected to the blood path (104, 106), and a drip chamber (114) and a blood pump (110) in the blood path (104, 106), the improvement comprising:

• a first sterile ultrafilter (44) provided between the dialysis solution path (22) and the connecting line (74), a second sterile ultrafilter (78) provided in the connecting line (74), and a substituate pump (76) connected between the first and second sterile ultrafilters (44, 78) for supplying hemofiltration replacement fluid to replace lost ultrafiltrate caused by action of said substituate pump (76) to the blood path.