A device for establishing venous inflow to a blood reservoir of an extracorporeal blood circulation system includes a restricting unit for gradually closing a venous inflow line and a vacuum unit for supplying vacuum to the blood reservoir. The device includes a control unit that supplies a first actuating signal to the restricting unit for restricting venous inflow to the blood reservoir and supplies a second actuating signal to the vacuum unit for establishing a degree of vacuum within the blood reservoir.
