Harmless wireless energy transmission to implant

An apparatus for wireless transfer of energy from outside a human's or animal's body to an energy consuming medical device (17) implanted in the human's or animal's body, comprising a transmission device (1;

• 19,20) operable from outside the human's or animal's body for transmission of an alternating magnetic field, and a receiver (3;
• 15;
• 21) implantable in the human's or animal's body for receiving and drawing energy from the alternating magnetic field to be supplied to the energy consuming implanted medical device, the transmission device including at least one coil (6) for generating the alternating magnetic field in a desired direction towards the receiver, the coil having a longitudinal extension, a front end to be directed towards the receiver and a rear to be directed away from the receiver, characterized by at least one shield (7) adapted to shield the environment from the alternating magnetic field generated by the coil (6) except at the front end of the coil (6), the shield including a magnetizable core (8) extending in the coil and a magnetizable casing (9) integrated with the core and surrounding the rear end of the coil and the circumference of the coil along at least a portion of the longitudinal extension of the coil.

A method for harmless wireless transfer of energy to an energy consuming medical device (17) implanted in a human's or animal's body, comprising implanting in the human or animal a receiver (3;

• 15;
• 21) capable of receiving and drawing energy from an alternating magnetic field to be supplied to the energy consuming medical device, providing an external transmission device (1;
• 19,20) capable of transmitting the alternating magnetic field and including a coil (6) having a longitudinal extension, a front end and a rear end, positioning the transmission device relative to the body so that the front end of the coil is directed towards the receiver and the rear end of the coil is directed away from the receiver, and transmitting by means of the transmission device the alternating magnetic field to the implanted receiver, characterized by shielding by means of a shield (7) the environment from the alternating magnetic field generated by the coil (6) except at the front end of the coil (6), the shield including a magnetizable core (8) extending in the coil of the transmission device and a magnetizable casing integrated with the core of the transmission device and surrounding the rear end of the coil and the circumference of the coil along at least a portion of the longitudinal extension of the coil.