A device for the treatment of human or animal tissue by means of a movable instrument is disclosed. The device comprises means for generating a magnetic stator field, in which the tissue is located. For example, the means for generating the magnetic stator field may be a magnetic resonance tomograph (MRT). At least one conductor loop is provided on or in the instrument, and a generator is provided for generating a current that flows through the conductor loop in order to generate a magnetic useful field, which, in conjunction with the stator field, generates a resulting action for applying a useful force to the instrument.
