The present invention relates to a medical device comprising an artificial contractile structure which may be advantageously used to assist the functioning of a hollow organ.Said medical device comprises an artificial contractile structure comprising at least one contractile element (100) adapted to contract an organ, in such way that said contractile element (100) is in a resting or in an activated position, at least one actuator designed to activate said contractile structure, and at least one source of energy for powering said actuator. Said actuator comprises actuating means designed in such a way that the energy consumption of said medical device is between 50 mAh/year and 2 000 mAh/year for a pressure applied by the contractile element on the organ comprised between 0.1 N/cm2 and 5 N/cm2.
