Research On Orthopaedic Surgery Navigation Technology Based On CT Image

Traditional orthopaedic surgery has a high failure rate because doctors cannot understand the real-time process.The application of Orthopaedic Surgery Robot improves this situation.Orthopaedic surgical navigation system,as the key of surgical robot,significantly improves the operation speed and success rate by helping doctors establish surgical planning before operation and providing accurate positioning information during operation,which has been widely concerned by researchers and medical manufacturers at home and abroad.Therefore,taking spinal surgery as the research object,this paper makes an in-depth study on CT image visualization technology,operation planning method,image registration method and optical positioning technology involved in orthopaedic surgery navigation technology based on CT image.The main research contents and conclusions of this paper are as follows:(1)This paper realizes the three-dimensional visualization of high-quality spine model.Firstly,by analyzing the imaging principle of CT image,the reading and display of CT image are realized,and the clear spine image is obtained with the help of window width and window level adjustment technology.Then,based on the region growing method and the principle of image color mapping,the spine image segmentation is realized.Finally,by studying the principle of surface rendering and volume rendering,the three-dimensional reconstruction of spine model is realized.The traditional flying algorithm is used to improve the rendering speed by 71.7%.(2)By analyzing the key methods and theories involved in the surgery planning system,this paper provides a basis for building the orthopaedic surgery planning system.Firstly,by studying the principle of image measurement and the virtual cutting of three-dimensional model,the interactive cutting between the angle and distance measurement of the model and any plane of the model is realized.Then,by analyzing the transformation principle of computer graphics coordinate system,the virtual spinal surgery simulation is realized.Finally,the principle of virtual collision detection is studied.Based on the OBB bounding box method,a two-step method is proposed to realize the collision detection function of spine model.Experiments show that this method takes into account both good interactivity and accuracy.(3)In this paper,the positioning principle of surgical navigation system is deeply studied,and a fast CT image registration method is proposed.Firstly,the optical positioning principle of binocular camera and ICP registration principle based on surface matching are studied;Then,based on the traditional ICP registration algorithm,a fast surface registration method is proposed.That is,the initial registration is completed by combining the key point idea and the sampling consistency principle.In the accurate registration stage,the k-d tree is used to speed up the search for the nearest neighbor point pair,and a certain proportion of false matching points are eliminated in the iterative process.Finally,through the experimental study of spine point cloud registration,the results show that the accuracy of this method is improved by 70.5%compared with the traditional ICP algorithm.The registration time was reduced from 177.8 s to 41.2 s.(4)Based on the research of surgical planning and surgical positioning technology,a surgical navigation system is established in this paper.Firstly,a binocular camera platform is built,and a marker recognition method is proposed;This method identifies the center of the mark and obtains its pixel coordinates by adaptive threshold segmentation and calculating image moment.Then,the camera calibration is completed based on Zhang Zhengyou calibration method,and the spatial pose of the marker is calculated by using the binocular camera positioning principle and singular value decomposition(SVD)method.The positioning experimental results show that the average error of this method is 0.1646 mm,which meets the requirements of surgery.Finally,the navigation software of spinal surgery is designed and developed,and the effectiveness of the system is verified by simulating the process of spinal surgery.