Patent ID: 8870804

Claim:
A blood treatment apparatus, comprising: a blood treatment unit, at least one fluid pump configured to pass a blood treatment fluid through the blood treatment unit, and at least one blood pump configured to extract untreated blood from a blood source, pass extracted blood through the blood treatment unit and deliver treated blood to a target vessel, wherein the at least one blood pump comprises a pumping chamber and a flexible impermeable member separating the pumping chamber into a first accumulation container and a second accumulation container, the flexible impermeable member being movable within the pumping chamber so as to vary a volume relationship between the first and second accumulation containers, the second accumulation container being configured to receive an amount of the blood treatment fluid to act on the flexible impermeable member and thus pump blood from the first accumulation container, a least one pressure measuring device arranged to sense a pressure of the blood treatment fluid in a blood treatment fluid passage including the second accumulation container and at least one conduit for the blood treatment fluid, wherein the at least one pressure measuring device is arranged to register a pressure parameter representing a pressure level of the blood based on a pressure measurement of the blood treatment fluid.