人工关节假体与宿主骨接触面积的研究
发布时间：2018-09-12 17:38
【摘要】：人工髋关节置换术成功在临床上应用之后,术后导致的临床并发症一直被人们广泛关注。最常见的后遗症就是假体的无菌性松动及下沉。引发此问题的原因非常多,像假体规格尺寸、手术过程中的人为因素、假体附近出现的骨骼溶解以及骨疏松等等。人工关节假体和其宿主骨接触面积的大小直接决定了关节假体和宿主骨二者负重的传递及分布,它在判断假体是否松动下沉及其是否可以长久固定有至关重要的作用。本文以人工关节假体C T图像为数据源,在对图像进行处理的基础上,计算假体与宿主骨的接触面积,分析接触面积大小对关节假体松动的影响,帮助医生判断假体的稳定性,及早确定假体的松动状况,为后续治疗提供可靠的依据。本文主要从以下几个展开研究工作:1.医学图像的预处理:患者携带的金属物体会引起C T重建图像中出现金属伪影,严重影响图像质量。金属伪影对后续图像三维重建以及接触面积的计算会产生直接或间接的影响,图像中伪影的去除不可或缺。本文找到了一种基于K均值聚类与迭代修正的C T金属伪影去除算法。首先,利用于K均值聚类法分割出金属,并结合线性插值修正投影数据,得到一张预处理图像,接着以此为基础进行迭代校正,迭代处理时通过各向异性平滑滤波来优化图像质量,通过多次迭代后得到目标图像。实验表明,相比于传统的分割和插值方法,本文方法能够更加准确的分割出金属物体和有效的去除金属伪影,且不会引入新的条纹伪影。2.医学图像的三维重建:在对医学图像进行重建的过程中传统三维面绘制移动立方体(M C)算法速度很缓慢、组织分离比较难,本文提出了一种改进的移动立方体算法。该算法根据人体器官相连的特征,首先挑选一些种子体元,然后依据这些种子衍生出器官全部等值面,从而减少了对没用体元的搜寻;同时,通过n次等分点法代替线性插值求解法向量和等值点坐标,缩减了运算次数。提高了算法的执行效率。重建出人工关节假体与宿主骨三维模型。为接触面积的计算奠定基础。3.接触面积的计算:在三维重建模型的基础上,通过结合有限元接触分析理论和网格划分软件求出接触面积。算法将建立好的三维模型以I G S格式导入到网格划分软件H y p e r m e s h 1 0.0中,对模型进行网格划分。并在有限元接触分析的基本理论上将假体和股骨接触部分的网格节点一一对应,计算出网格的节点数和单元数,进而估算出接触面积。并通过对假体与宿主骨不同接触区域面积大小的计算,讨论接触面积大小与松动的关系。具有较强的临床意义和价值。
[Abstract]:After the successful application of artificial hip arthroplasty, the postoperative complications have been paid more and more attention. The most common sequelae are aseptic loosening and sinking of the prosthesis. There are many reasons for this problem, such as the size of the prosthesis, artificial factors during the operation, bone dissolution near the prosthesis, and osteoporosis and so on. The size of the contact area between the prosthesis and its host bone directly determines the weight transfer and distribution between the prosthesis and the host bone. It plays an important role in judging whether the prosthesis is loosening and sinking and whether the prosthesis can be fixed for a long time. Based on the CT image of artificial joint prosthesis, the contact area between prosthesis and host bone is calculated, and the influence of contact area on the loosening of prosthesis is analyzed to help doctors judge the stability of prosthesis. To determine the loosening condition of prosthesis as early as possible, and to provide reliable basis for subsequent treatment. This article mainly starts the research work from the following several. Medical image preprocessing: metal objects carried by patients will cause metal artifacts in CT reconstruction images, which seriously affect the image quality. Metal artifacts have a direct or indirect effect on the 3D reconstruction and the calculation of contact area, so the removal of artifacts is indispensable. In this paper, an algorithm for removing artifacts of C T metal based on K-means clustering and iterative correction is found. Firstly, the metal is segmented by K-means clustering method, and a preprocessed image is obtained by combining with the linear interpolation correction projection data, and then the iterative correction is carried out on the basis of this method. The image quality is optimized by anisotropic smoothing filter during iterative processing, and the target image is obtained by multiple iterations. Experiments show that compared with the traditional segmentation and interpolation methods, this method can segment metal objects more accurately and remove metal artifacts effectively, and no new fringe artifacts. 2. Three-dimensional reconstruction of medical image: in the process of medical image reconstruction, the speed of traditional 3D surface rendering moving cube (M C) algorithm is very slow, and the organization separation is difficult. In this paper, an improved moving cube algorithm is proposed. According to the characteristics of human organs connecting, the algorithm first selects some seed elements, and then derives the whole isosurface of organs according to these seeds, thus reducing the search for useless bodies; at the same time, The normal vector and equivalent point coordinates are solved by the n-degree equipartition point method instead of the linear interpolation method, and the number of operations is reduced. The efficiency of the algorithm is improved. The three-dimensional model of artificial joint prosthesis and host bone was reconstructed. Lay the foundation for the calculation of contact area. Calculation of contact area: based on 3D reconstruction model, contact area is calculated by combining finite element contact analysis theory and meshing software. The established 3D model is imported into the grid division software H y p e r m e s h 10.0 by I G S format, and the model is meshed. In the basic theory of finite element contact analysis, the mesh nodes of the prosthesis and the femur contact part are mapped one-to-one, the number of nodes and the number of elements of the mesh are calculated, and the contact area is estimated. The relationship between contact area and loosening was discussed by calculating the contact area between prosthesis and host bone. It has strong clinical significance and value.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R687.4;TP391.41
本文编号：2239761
[Abstract]:After the successful application of artificial hip arthroplasty, the postoperative complications have been paid more and more attention. The most common sequelae are aseptic loosening and sinking of the prosthesis. There are many reasons for this problem, such as the size of the prosthesis, artificial factors during the operation, bone dissolution near the prosthesis, and osteoporosis and so on. The size of the contact area between the prosthesis and its host bone directly determines the weight transfer and distribution between the prosthesis and the host bone. It plays an important role in judging whether the prosthesis is loosening and sinking and whether the prosthesis can be fixed for a long time. Based on the CT image of artificial joint prosthesis, the contact area between prosthesis and host bone is calculated, and the influence of contact area on the loosening of prosthesis is analyzed to help doctors judge the stability of prosthesis. To determine the loosening condition of prosthesis as early as possible, and to provide reliable basis for subsequent treatment. This article mainly starts the research work from the following several. Medical image preprocessing: metal objects carried by patients will cause metal artifacts in CT reconstruction images, which seriously affect the image quality. Metal artifacts have a direct or indirect effect on the 3D reconstruction and the calculation of contact area, so the removal of artifacts is indispensable. In this paper, an algorithm for removing artifacts of C T metal based on K-means clustering and iterative correction is found. Firstly, the metal is segmented by K-means clustering method, and a preprocessed image is obtained by combining with the linear interpolation correction projection data, and then the iterative correction is carried out on the basis of this method. The image quality is optimized by anisotropic smoothing filter during iterative processing, and the target image is obtained by multiple iterations. Experiments show that compared with the traditional segmentation and interpolation methods, this method can segment metal objects more accurately and remove metal artifacts effectively, and no new fringe artifacts. 2. Three-dimensional reconstruction of medical image: in the process of medical image reconstruction, the speed of traditional 3D surface rendering moving cube (M C) algorithm is very slow, and the organization separation is difficult. In this paper, an improved moving cube algorithm is proposed. According to the characteristics of human organs connecting, the algorithm first selects some seed elements, and then derives the whole isosurface of organs according to these seeds, thus reducing the search for useless bodies; at the same time, The normal vector and equivalent point coordinates are solved by the n-degree equipartition point method instead of the linear interpolation method, and the number of operations is reduced. The efficiency of the algorithm is improved. The three-dimensional model of artificial joint prosthesis and host bone was reconstructed. Lay the foundation for the calculation of contact area. Calculation of contact area: based on 3D reconstruction model, contact area is calculated by combining finite element contact analysis theory and meshing software. The established 3D model is imported into the grid division software H y p e r m e s h 10.0 by I G S format, and the model is meshed. In the basic theory of finite element contact analysis, the mesh nodes of the prosthesis and the femur contact part are mapped one-to-one, the number of nodes and the number of elements of the mesh are calculated, and the contact area is estimated. The relationship between contact area and loosening was discussed by calculating the contact area between prosthesis and host bone. It has strong clinical significance and value.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R687.4;TP391.41
【参考文献】
相关期刊论文 前1条
1 李鸣;;一种改进的各向异性扩散去噪算法[J];光电子技术;2014年01期
，本文编号：2239761
本文链接：https://www.wllwen.com/yixuelunwen/waikelunwen/2239761.html
最近更新
教材专著
