Instantaneous and Markerless Registration for Mandible Reconstruction Robot With Fibular Holder

Robotic-assisted mandible reconstruction surgery is reported to achieve a more precise fibula osteotomy. However, intraoperative registration of the fibula with preoperative imaging is the key to achieving precision. Although methods such as probe scanning, optical navigation, and point cloud recognition are available, the reliability and efficiency of registration are low due to the sparse anatomical features and bone membrane covering on the fibular surface. Fibular shaping involves multiple bone segment osteotomies, and therefore, the design of fibular holder is necessary to achieve stable shaping. Based on these facts, an instantaneous and markerless registration based on the fibular holder is proposed, consisting of the initial alignment and refinement. The initial alignment using the point cloud or the holder to locate the fibula. The refinement, based on mechanical constraints, is developed and solved iteratively, utilizing the mechanical constraints between the fibula and the V-shaped mounts of the fibular holder. The accuracy of the approach is evaluated through simulations, model experiments and animal experiments. The results indicated that this algorithm provides higher accuracy and efficiency. This method can achieve non-invasive, efficient, and highly precise fibular registration in mandibular reconstruction surgery.