Method and apparatus for location finding of electrodes placed onto the body, particularly to the head

An apparatus for finding locations of electrodes attached to a head, comprising:

• a plurality of electrodes;
• at least one first coil attached to each electrode, said at least one first coils attached to the electrodes forming a first coil group to be localized;
• a plurality of second coils adapted to be arranged in a vicinity of the electrodes so that a position of said second coils is uniquely known, said second coils forming a fixed second coil group;
• current means for generating a magnetic field with either said first coil group or said second coil group, whereby said coil group not generating the magnetic field is used for detecting the induced magnetic field;
• measuring means electronically connected to said coil group detecting the induced magnetic field, for detecting a signal representing the induced magnetic field;
• and
• data processing means , connected to said measuring means, for processing said signal to determine the position of the electrodes.