MEDICAL SYSTEM COMPRISING IMPLANTS

A medical system comprising internal parts for implantation in a patient and external parts for use externally to the patient is provided. The external parts comprises an external energy source for wirelessly transmitting energy to the internal parts. The internal parts comprises an electrically powered medical device, an energy receiver for receiving energy for the medical device from the external energy source, and an internal control unit for controlling the internal parts. The internal control unit is adapted to determine at least one parameter relating to the wireless energy transfer, wherein the internal control unit is arranged to control the energy transfer based on the at least one parameter.