Patent ID: 9572920
Date: 2017-02-21
CPC Classifications: A61M,Y10T

Claim:
1. An apparatus for blood treatment, the apparatus comprising: a supply system of a treatment fluid; and a disposable for use in blood treatment, the disposable comprising a blood treatment unit for connection to the supply system that is operable to pump the treatment fluid through the blood treatment unit during the blood treatment, a blood withdrawal connector which is connected to the blood treatment unit via a blood withdrawal line, and a blood return connector which is connected to the blood treatment unit via a blood return line, wherein one of the blood withdrawal and blood return lines comprises a membrane pump arrangement operable to pump blood through the blood treatment unit, wherein the membrane pump arrangement comprises first and second blood line branches that are connected at an upstream end and at a downstream end, wherein a first membrane pump is arranged in the first blood line branch, and a second membrane pump is arranged in the second blood line branch, wherein each of the first and second membrane pumps comprises a pumping chamber and a flexible member separating the pumping chamber into a blood compartment and a working fluid compartment and being movable within the pumping chamber so as to vary the volume relationship between the blood compartment and the working fluid compartment, wherein the blood compartment is arranged for fluid communication with the upstream and downstream ends, and the working fluid compartment is arranged for fluid communication with the supply system, and wherein each of the first and second membrane pumps comprises an upstream valve and a downstream valve for controlling blood flow between the blood compartment and the upstream end and the downstream end, respectively, and wherein the disposable is configurable for operation in a first blood access mode, in which the blood withdrawal and blood return connectors are connected to a single access device, and the membrane pump arrangement is operable to alternately draw blood from the upstream end, and to pump blood through the downstream end, thereby generating a pulsatile flow of blood through the blood treatment unit, and in a second blood access mode, in which the blood withdrawal and blood return connectors are connected to a first and a second access device, respectively, and the membrane pump arrangement is operable to concurrently draw blood from the upstream end and pump blood through the downstream end, thereby generating an essentially continuous flow of blood through the blood treatment unit, wherein the membrane pump arrangement is configured for connection to the supply system such that alternating flows of treatment fluid generated by the supply system and supplied to the first and second membrane pumps causes the membrane pump arrangement to generate the pulsatile flow of blood in the first mode and the essentially continuous flow of blood in the second mode, and wherein one of the upstream or downstream valves is controllable to selectively open for blood flow by application of positive pressure to the treatment fluid, and (b) the other of the upstream or downstream valves is controllable to selectively block blood flow by application of positive pressure to the treatment fluid.