[Experimental study of three dimensional navigation assisted spinal surgery by multi-segment registration technology based on structured light scanning].

Objective To study the registration method based on structured light scanning for navigation assisted spinal surgery and assess its accuracy so as to construct a registration system for the navigation assisted spinal surgery using structured light scanning. Methods Both the computed tomographic (CT) dataset and the structured light scanning images of thoracic vertebra were obtained. The preregistration and multi-segment iterative closest point (ICP) algorithm were used for the registration of CT images and structured light images. Four segmentations were selected from the surface of thoracic vertebra and placed into different combinations. The accuracy for each combination was studied. Noise and perturbation were exerted to structured light and registration accuracy was studied. And calf vertebra was used for further verification. Results A combination of pre-registration and multi-segment iterative closest point (ICP) algorithm was competent for the registration of CT scanning data and the structured light scanning data. The registration error was less than 1 mm when two and more segments were selected for registration combination. The registration error was less than 1 mm when noise was exerted. Conclusion With a high accuracy and a perturbation resistance, a combination of pre-registration and multi-segment registration algorithm based on structured light scanning is competent for the registration of CT scanning data and structured light scanning data. Key words: Therapy, computer-assisted;  Orthopaedic procedure;  Algorithms;  Spine