A control device for a ventricular assist device (VAD) with settable speed levels. The control device includes an input configured to receive at least one measuring signal related to a physiological condition of the circulatory system of a patient receiving heart assistance by the VAD, where the control device is configured to derive an actual value of at least one characteristic parameter of the heart from one or more of the at least one measuring signal and to provide a refined actual value of the at least one characteristic parameter in which effects of physiologically caused fluctuations are eliminated or reduced. The control device further includes an output configured to output an updated setting value for the speed level, where the control device is configured to produce the updated setting value based on the refined actual value and a predeterminable set-point value.