A heart lung machine (HLM) includes: a pump actuator; an actuator control unit (ACU) operably connected to the pump actuator; a processing unit configured to receive a set of parameter data from the actuator; a display device configured to present a subset of the set of parameter data; and an input control device operably connected to the pump actuator. The input control device includes a rotatable knob. The ACU may be configured to: determine that the pump actuator has been stopped in response to a pump-stop trigger event; determine that the rotatable knob has been rotated to a first position; and in response to determining that the rotatable knob has been rotated to the first position, starting the pump actuator.