A control device (100) for a ventricular assist device, VAD (50), with settable speed levels, the control device (100) comprising an input (101) configured to receive at least one measuring signal (LVP meas ) related to a physiological condition of the circulatory system of a patient (P) receiving heart assistance by the VAD (50), wherein the control device (100) is configured to derive an actual value (EDLVP； FG) of at least one characteristic parameter of the heart (H) from one or more of the at least one measuring signal (LVP meas) and to provide a refined actual value (EDLVP*； FG*) of the at least one characteristic parameter in which effects of physiologically caused fluctuations are eliminated or reduced； and an output (105) configured to output an updated setting value (n VAD set ) for the speed level, wherein the control device (100) is configured to produce the updated setting value (n VAD set ) based on the refined actual value (EDLVP*； FG*) and a predeterminable set-point value (EDLVP set ； FG set ). A VAD (50) for assistance of a heart, comprising the control device (100), wherein the VAD (50) is preferably a non-pulsatile rotational blood pump, wherein further preferably the blood pump is catheter-based. A method for obtaining a refined actual value of at least one characteristic parameter of the heart (H), the method comprising receiving at least one measuring signal (LVP meas ) related to a physiological condition of the circulatory system of a patient (P)； deriving an actual value (EDLVP； FG) of at least one characteristic parameter of the heart (H) from one or more of the at least one measuring signal (LVP meas) ； processing the actual value (EDLVP； FG) or the one or more of the at least one measuring signal (LVP meas ) to provide the refined actual value (EDLVP*； FG*) in which physiologically caused fluctuations are eliminated or reduced. A method for controlling the speed level of a ventricular assist device, VAD (50), with settable speed level
