A Noncontact Laser-Guided System for Endoscopic Computer-Assisted Sinus Surgery

The limited size of the nose leads to frequent instrument changes in navigated endonasal sinus surgery. Tracked instruments provide limited accuracy, and the pointer gives no navigation information during tissue removal. To overcome information loss, laser triangulation was integrated into navigation information. Accuracy and reliability of the laser-assisted distance-measuring system were evaluated within the distance of 0 and 20 mm. System accuracy of the laser endoscope was compared with a standard pointer using registration via bone screws and surface matching. Accuracy of the laser was 0.12 mm +/- 0.12 mm with a reliability of 0.2 mm. The system accuracy of the laser endoscope was 0.59 mm +/- 0.16 mm using bone screw registration and 0.64 mm +/- 0.22 mm using surface matching. Additionally, laser endoscope is more accurate compared with the pointer using bone screw registration. Overall, navigation information was successfully integrated into an endoscope by laser triangulation with encouraging results.