Systems, methods and computer program products for detecting and re-personalizing are provided herein. The transmitters emit light signals that are received by the photodiode receivers. A value of a first torque dependent function is calculated, based on the rotational speed, the value of the input torque and a limit value of the input torque, the value of the input torque exceeding the limit value of the input torque. The pump draws additional disinfectant from the reservoir as needed.