The present invention relates to a medical device comprising an artificialcontractile structure which may be advantageously used to assist thefunctioning of ahollow organ. Said medical device comprises an artificial contractilestructurecomprising at least one contractile element (100) adapted to contract anorgan, in suchway that said contractile element (100) is in a resting or in an activatedposition, atleast one actuator designed to activate said contractile structure, and atleast onesource of energy for powering said actuator. The ratio "current which isneeded tomaintain the contractile element in its activated position and in its restingposition/ current which is needed to change the position of the contractile element"is less than1/500, preferably less than 1/800, and more preferably less than 1/1000. Saidmedicaldevice further comprises means for reducing corrosion of the medical device.
