The invention concerns a control device (100) for controlling a blood flow Q VAD (t) of a percutaneous inserable ventricular assist device, VAD, (50), the VAD (50) comprising a pump unit (52) with a drive unit (51) for driving the pump unit and configured to convey blood from a blood flow inlet (54) towards a blood flow outlet (56), wherein the control device (100) is configured to operate the VAD (50) in a selectable zero-flow control mode, wherein a blood flow command signal Q VAD set (t) is selected, and the control device comprises a first controller (401) and a second controller (402), wherein the first controller (401) is configured to control the blood flow Q VAD (t) by adjusting a speed command signal n VAD set (t) for the drive unit (51), and the second controller (402) is configured to control a drive speed n VAD (t) of the drive unit (51). Further, the invention concerns a corresponding method for controlling a blood flow Q VAD (t) of a percutaneous insertable VAD (50), as well as a control device (100) configured to carry out the method. Finally, the invention concerns a system comprising a VAD (50) for assistance of a heart and the control device (100) controlling the VAD (50).
