An endoscopic surgical navigation system comprises a tracking subsystem to capture data representing positions and orientations of a flexible endoscope during an endoscopic procedure, to allow coregistration of live endoscopic video with intra-operative and/or pre-operative scan images. Positions and...http://www.google.de/patents/US7824328?utm_source=gb-gplus-sharePatent US7824328 - Method and apparatus for tracking a surgical instrument during surgery
