Research On Segmentation And Registration Algorithms And Their Medical Applications

The continuous development of computer technology has brought about changes in the medical industry,and the computer-aided medical system and its corresponding algorithms have become a research hotspot.This paper studies the segmentation and registration algorithms commonly used in the computer-aided medical system and introduces the application scenarios of the two algorithms with the computer-aided orthodontic system and computer-aided pedicle screw insertion surgery as the starting point.The main work of this paper is as follows:(1)Study the segmentation algorithm of the 3D mesh model.Based on the shortest path algorithm(Dijkstra),the storage structure and priority queue-based optimization of the Dijkstra algorithm was proposed,and a method to get the topology data of the mesh model was proposed.Then,the Dijkstra algorithm was applied to search the shortest path on the mesh model,and the shortest path was used as the segmentation path of the model.The segmentation of the 3D mesh model is realized.(2)To study the segmentation method of dental models.By analyzing the curvature of the dental model,the definition of the most concave principal curvature was proposed,and the three calculation formulas of model edge weights based on the transformation of the most concave principal curvature was designed.Then,the proposed mesh model segmentation algorithm was used to calculate the tooth segmentation path through the gingival line according to the manually selected marking points.(3)Study the 3D model registration algorithm based on full search.Solving the problem of the ICP algorithm requires a good initial position of the registration model,by calculating all possible model movements within a given space range,and choosing the best solution from all possible model movements to avoid the locally optimal solution.So that the ICP algorithm was given better rough registration results,and the point to plane ICP algorithm is used to calculate the precision registration results.(4)Application of registration algorithm in pedicle screw insertion surgery.Because of the unclear imaging observation caused by screw insertion in CT images,preoperative and postoperative vertebrae and 3D model of screw insertion was extracted from Mimics,and the postoperative model was registered on the preoperative model,to observe the surgical effect more clearly and intuitively from a 3D model.The operation process and examples were also given.