An volume of a patient can be mapped with a system operable to identify a plurality of locations and save a plurality of locations of a mapping instrument. The mapping instrument can include one or more electrodes that can sense a voltage that can be correlated to a three dimensional location of the...http://www.google.de/patents/US20090264727?utm_source=gb-gplus-sharePatent US20090264727 - METHOD AND APPARATUS FOR MAPPING A STRUCTURE
