A Novel Endoscopic Navigation System: Simultaneous Endoscope and Radial Ultrasound Probe Tracking Without External Trackers

Abstract

This paper develops a fully novel endoscopic navigation system that can simultaneously navigate a flexible endoscope and radial ultrasound miniature probe without using external tracking devices. Current navigated endoscopy (e.g., video- or electromagnetic-based navigation) usually tracks only the endoscope motion and inspects the interior of a body cavity or hollow organ and has no ability to visualize anatomical structures (e.g., pulmonary or abdominal lymph nodes) beyond the wall of the body cavity. To enhance endoscopic navigation, we introduce a radial ultrasound miniature probe that goes through the working channel of the endoscope to observe anatomical structures under the organ wall. However, the location of the ultrasound probe is difficult to determine inside the hollow organ. We propose a new navigation framework on the basis of video-volume registration, visual tracking, and ultrasound-volume alignment to simultaneously navigate the endoscope and probe in endoscopic interventions. Our framework can simultaneously and spatially synchronize pre-operative images, endoscopic video sequences, and ultrasound images to realize a fully new navigation system.