Live endoscopic video streams augmented for 3D-navigation

Abstract

Endoscopic and video-endoscopic procedures in ENT and neurosurgical interventions are ideally apt for navigation. 3D-Navigation with endoscopy satisfies the surgical demand of precise information regarding localization of instruments in the patient's anatomy. We provide a solution augmenting surgical performance and acceptance: a 3D-navigated (video-)endoscope armed with a Laser, providing a non-contact image-processing-based position-sensing. It is paradigmatically implemented for functional endoscopic sinus surgery (FESS) in ORL-surgery. Basically, a Laser beam crosses the endoscopic field-of-view and hits an anatomical structure. With known and calibrated geometry of the Naviscope the spot in the live video stream can be extracted to yield the spatial distance of the Laser spot in the patient relative to the distal tip of the endoscope along the optical axis, for a 0° endoscope (R. Wolf, Germany). This information can be displayed easily in a navigation system. For angled scopes straightforward analysis is required for implementing in a navigation system. The extracted positional information is combined with the appropriate FRE/TRE methodology and a stochastic predictor of clinical application accuracy. The combined position displayed is reflecting the estimated application accuracy in a variety of means like proportional 3Dbroadening of calculated cross-hair in the preoperative data sets that show the Laser spot's locus. Thus a "smeared" tip of the navigated tool in the data set can instruct a surgeon about the reliability of navigational information in an intuitive way. The whole system is IGSTK-based and runs with an optical tracker.