Patent ID: 8398859

Claim:
A hemodiafiltration device comprising a hemofilter, a first circuit for circulating a dialysis liquid through the hemofilter in a first direction of flow; a second circuit for circulating blood through the hemofilter in a second direction of flow; a liquids pump for injection of a substitution liquid into the first circuit so that the substitution liquid can be circulated through the hemofilter together with the dialysis liquid, said liquids pump being disposed upstream of the hemofilter with reference to the first direction of flow; a blood pump for injecting blood through the second circuit into the hemofilter, said blood pump being disposed upstream of the hemofilter with reference to the direction of flow of blood; said hemofilter comprising a semi-permeable membrane that separates blood in the second circuit from dialysis liquid in the first circuit; and means for selectively opening and closing the respective first and second circuits upstream and downstream of the hemofilter to enable generation in the hemofilter of either (i) a first pressure gradient, wherein toxic substances from the blood in the second circuit flow through the membrane into the dialysis liquid, or (ii) a second pressure gradient, wherein the substitution liquid injected by the pump into the first circuit flows through the membrane into the blood in the first circuit, wherein for generation of the second pressure gradient, the second circuit is closed upstream of the hemofilter and open downstream of the hemofilter with reference to the direction of flow of blood, and the first circuit is open upstream of the hemofilter and closed downstream of the hemofilter with reference to the direction of flow of the dialysis liquid, wherein the means comprises a first plurality of valves in the first circuit and a second plurality of valves in the second circuit; and wherein the hemofiltration device comprises a control unit for regulating the respective blood pump, liquids pump, and the first and second plurality of valves so as to control the flow of liquid from the first circuit through the membrane into the blood in the second circuit.