Research And Development Of Computer-assisted Surgery Navigation System

Computer-assisted surgery navigation system results from the participation of many scientists in different fields such as computer science, mathematics, mechanics, surgery, internal medicine and biomedicine engineering. It widens surgeons'scope and refreshes the conception of surgical instruments. In this thesis, the computer-assisted surgery system that we developed is introduced and some related techniques such as image processing, tri-dimensional display, image registration and space registration are discussed.The volume data processing and visualization are the basis of computer-assisted surgery navigation system. The volume data reconstruction method, image interpolation method and the display method of any section image are introduced. We emphasize on the study of model segmentation and reconstruction. In the aspect of segmentation the threshold method and region method are discussed. In the aspect of model surface reconstruction, the reconstruction methods based on slices and voxels are discussed with emphasis on iso-surface generation methods. Triangle simplification algorithm based on edge contraction is used to simplify the constructed models, which can speed up the three-dimensional display.Both space location and registration are the key techniques of the surgery navigation system. The registration in the navigation system includes multi-model medical image registration and space registration. As to the former, we emphasize on the mutual information method which improves the registration precision and needs less participation of the users. As to the latter, surface registration method and external marks method are discussed with emphasis on marks method. Least square method is used to find the best transformation between space and image, and the results show that better registration precision could be got.Finally, the computer-assisted surgery navigation system that we developed is presented. The system is designed based on modularization method. Modules are divided according to their functions. Each functional module is supplied in the form of COM or DLL. The division method of modules and the data structure design method are discussed. The detail functions of the system are introduced in the thesis.