Abstract: An apparatus for performing a specified task within the human body has an implanted electromagnetic device for use in conjunction with an external electromagnetic field. The electromagnetic device includes a drive member which is a rotor of an electric motor. The drive member, when located within an electromagnetic field, will drive a pump to pump fluid from a reservoir such as to a pair of prosthesis cylinders implanted in the penis. The external electromagnetic field is an AC stator that has an aperture for positioning over the rotor, which is located in a sealed housing implanted in the scrotum.