Towards Tracking by 2D-target Registration for Surgical Optical Tracking System.

Optical tracking system (OTS) is essential for surgical navigation and has been commonly employed in clinical practice due to high accuracy and precision. However, current OTS will be influenced by occlusion, which results in interruption of the surgical process. To address this question, we propose a tracking by 2D-target registration approach and utilize a multi-marker 2D-target and a stereo camera to carry out surgical instrument tracking. The proposed tracking approach tracks the multi-marker 2D-target in a 3D point cloud registration manner. As a result, OTS can track surgical instrument accurately and robustly by using the proposed tracking approach, even if a part of the markers are occluded. Simulations and experiments have been carried out to validate the feasibility and performance of the proposed approach. The results show that OTS can still track the instrument by using the proposed tracking approach even when 0 +/- 45.5% of the markers are occluded. The average tracking error of the proposed approach is 0.35 +/- 0.21mm.