Research On Simulation Matching Algorithm Of Artificial Joint Based On 3D Image

Before artificial joint replacement,it is one of the key problems to determine the fitness of prosthesis and joint bone tissue through the simulation matching in vitro.Based on this problem,this paper starts with the 3D image of the artificial joint,through the registration of the 3D data of the joint and the prosthesis,realizes the in vitro simulation matching.The simulation matching algorithm of artificial joint based on 3D image is divided into three stages: image preprocessing stage,3D point cloud registration stage and simulation matching stage.In the stage of image preprocessing,aiming at the problem of insufficient direction of traditional Prewitt operator template,on the basis of the existing eight direction template,the method of taking absolute value of template convolution is adopted to reduce the calculation of convolution value to four times,which makes up for the disadvantage that the eight direction template algorithm consumes too much time and improves the operation efficiency of the algorithm.At the same time,the absolute value difference is used as the approximate substitution of gradient value to further improve the anti noise ability of the algorithm.In the three-dimensional image registration stage,aiming at the dependence of ICP algorithm on the initial value,a three-stage registration method based on the combination of principal component analysis and iterative closest point algorithm is proposed.The PCA algorithm combined with the two ICP registration strategies are used to first process the registration data with PCA,then adjust the initial registration results with ICP algorithm,and finally adjust the initial registration results with ICP algorithm Adjust the attitude data to perform ICP registration again,so as to achieve the consistency of spatial coordinates of the data to be registered.In the simulation matching stage,the point cloud data of the patient's joint is fitted with the surface,and then the point cloud data of the prosthesis isoverlapped with the data of the prosthesis.The fitness of the prosthesis is evaluated by the degree of the overlap of the joint surface to realize the selection of the prosthesis model.In the last part of the experiment,two sets of knee CT data are used to analyze the feasibility of the artificial joint simulation matching algorithm based on three-dimensional image.The experimental results show that the proposed method can achieve the simulation matching between the joint and the prosthesis.