Design Of The Receptive Cavity Of Leg Prosthsis And Research On Alogorithm

The artificial limb is an important tool for patients with physical disability to move normally.However,few patients can use artificial limb.The main reason is that the prosthesis is mainly made by manual,which has the problems of high cost,long manufacturing cycle and difficult to guarantee the comfort.In order to solve these problems,this paper takes the patients’ leg stump as the research object,and the design scheme of the receptive cavity is proposed.This scheme is that using laser scanning,three-dimensional surface reconstruction,finite element analysis and 3D printing technology to design and make receptive cavity.The main work of this paper is as follows:(1)Based on the research of the structure of the stump and the division of the bearing area of the stump,and according to the requirements of the design of the receptive cavity,the design scheme of the prosthetic socket is put forward.(2)Use laser scanning to collect the data of the stump,and perform denoising and streamlined preprocessing.In the process of denoising,statistical filtering is used to remove large-scale noise,and then bilateral filtering is used to remove small-scale noise.In the process of simplification,an improved algorithm combining the bounding box reduction and curvature reduction is proposed.The point cloud data is divided into flat region and abrupt region according to the curvature,then the flat region is simplified by the bounding box reduction,and the abrupt region is simplified by the curvature reduction.This algorithm not only retains the feature points of point cloud data,but also does not cause local holes,and has a high reduction rate.(3)The delaunay three-dimensional surface reconstruction algorithm and poissonthree-dimensional surface reconstruction algorithm are studied,and the improved delaunay three-dimensional surface reconstruction algorithm is proposed to reconstruct the three-dimensional surface of the stump.Firstly,the point cloud data is segmented by the spatial bounding box method,then use the local Delaunay three-dimensional surface reconstruction to reconstruction surface,and splice each local surface,finally,fill the holes.This algorithm speeds up the establishment of spatial index and makes the surface reconstruction better.(4)According to the surface of the stump,the receptive cavity and bushing model are generated.Then,according to the images collected by CT,the residual limb model is established by medical image processing software and surface repair software,then the residual limb and the receptive cavity model are assembled to get the residual limb receptive cavity model.The model is analyzed by finite element method,and the receptive cavity is modified until it reaches the requirement of reasonable bearing.(5)3D printing technology is used to manufacture the receptive cavity.According to the results of the stress test while standing and the effect of the patients’ trial wearing,the receptive cavity is comfortable to wear and can meet the needs of the patients.So the design scheme has strong reliability and certain application value.