Patent ID: 7488301

Claim:
A method for the return of blood from a blood treatment apparatus that includes a blood treatment element configured for hemodiafiltration, a first line and a second line each having an outlet, a blood pump, a first valve arranged in the first line, a second valve arranged in the second line, and a predilution port configured to feed a substituate fluid, with a substituate supply line connected to the predilution port and to a substitutate pump, the method comprising the steps of: opening the first valve in the first line and closing the second valve in the second line; configuring the blood pump for feedthrough operation or pressure control operation and operating the substituate pump to displace the blood with transported substituate fluid in a volume-controlled manner until the displaced blood has reached the first line outlet; discontinuing operation of the blood pump, closing the first valve, and opening the second valve; and operating the substituate pump to displace the blood through the second line and the blood treatment element with transported substituate fluid in a volume-controlled manner until the displaced blood has reached the second line outlet.