Patent ID: 8688229

Claim:
An alternating magnetic field application device for heating magnetic or magnetizable substances in a biological tissue, comprising a large applicator, comprising a magnetic yoke and two oppositely situated first and second pole shoes on the magnetic yoke wherein the first and second pole shoes are separated by an exposure gap wherein first and second magnetic coils are respectively associated with the first and second pole shoes, with a large applicator control unit connected to the large applicator and configured for supplying alternating current having a given amplitude, frequency, and phase position in order to generate a substantially homogenous alternating magnetic field of a given field strength in the exposure gap, wherein the biological tissue to be exposed to the magnetic field may be brought into the exposure gap as an exposure target volume, wherein a field concentrator located in the exposure gap is situated in the immediate proximity of the biological tissue to be exposed to the magnetic field as the exposure target volume the field concentrator concentrating the alternating magnetic field of the large applicator in the target volume and thereby locally enhancing the alternating magnetic field at the immediate proximity of the biological tissue, wherein the field concentrator is in the form of an active field concentrator and includes at least one magnetic coil, wherein the at least one magnetic coil is aligned in such a way that the field lines of the active field concentrator and of the large applicator are directed in approximately the same direction, and a field concentrator control unit is provided, by means of which the at least one magnetic coil is supplied with a synchronized alternating current which is in phase with and of the same frequency as the alternating current of the large applicator.