An invasive imaging system employs a self-contained RF transmitter attached to an invasive device which allows tracking of the invasive device within a subject without physical connections to a tracking/display system and without the use of ionizing rays. An imaging system obtains a medical diagnostic...http://www.google.de/patents/US5445150?utm_source=gb-gplus-sharePatent US5445150 - Invasive system employing a radiofrequency tracking system
