Augmented Reality Navigation With Automatic Marker-Free Image Registration Using 3-D Image Overlay for Dental Surgery

TLDR

Computer‑assisted oral and maxillofacial surgery has rapidly evolved, yet current navigation still suffers from bulky sensors, difficult registration, patient movement, loss of depth perception, and low accuracy. We present an augmented reality navigation system for dental surgery that automatically registers images without markers using 3‑D overlay and stereo tracking. The system employs a custom stereo camera to track patient and instrument, performs marker‑free registration via patient tracking and real‑time 3‑D contour matching, overlays the patient’s 3‑D anatomy and instrument onto the surgical field through a half‑silvered mirror, and renders real‑time autostereoscopic 3‑D images with a consumer GPU to provide stereo and motion parallax for depth perception. Experiments show the system achieves an overall image overlay error of 0.71 mm.

Abstract

Computer-assisted oral and maxillofacial surgery (OMS) has been rapidly evolving since the last decade. State-of-the-art surgical navigation in OMS still suffers from bulky tracking sensors, troublesome image registration procedures, patient movement, loss of depth perception in visual guidance, and low navigation accuracy. We present an augmented reality navigation system with automatic marker-free image registration using 3-D image overlay and stereo tracking for dental surgery. A customized stereo camera is designed to track both the patient and instrument. Image registration is performed by patient tracking and real-time 3-D contour matching, without requiring any fiducial and reference markers. Real-time autostereoscopic 3-D imaging is implemented with the help of a consumer-level graphics processing unit. The resulting 3-D image of the patient's anatomy is overlaid on the surgical site by a half-silvered mirror using image registration and IP-camera registration to guide the surgeon by exposing hidden critical structures. The 3-D image of the surgical instrument is also overlaid over the real one for an augmented display. The 3-D images present both stereo and motion parallax from which depth perception can be obtained. Experiments were performed to evaluate various aspects of the system; the overall image overlay error of the proposed system was 0.71 mm.