人工關節(jié)假體與宿主骨接觸面積的研究
發(fā)布時間：2018-09-12 17:38
【摘要】：人工髖關節(jié)置換術成功在臨床上應用之后,術后導致的臨床并發(fā)癥一直被人們廣泛關注。最常見的后遺癥就是假體的無菌性松動及下沉。引發(fā)此問題的原因非常多,像假體規(guī)格尺寸、手術過程中的人為因素、假體附近出現(xiàn)的骨骼溶解以及骨疏松等等。人工關節(jié)假體和其宿主骨接觸面積的大小直接決定了關節(jié)假體和宿主骨二者負重的傳遞及分布,它在判斷假體是否松動下沉及其是否可以長久固定有至關重要的作用。本文以人工關節(jié)假體C T圖像為數(shù)據(jù)源,在對圖像進行處理的基礎上,計算假體與宿主骨的接觸面積,分析接觸面積大小對關節(jié)假體松動的影響,幫助醫(yī)生判斷假體的穩(wěn)定性,及早確定假體的松動狀況,為后續(xù)治療提供可靠的依據(jù)。本文主要從以下幾個展開研究工作:1.醫(yī)學圖像的預處理:患者攜帶的金屬物體會引起C T重建圖像中出現(xiàn)金屬偽影,嚴重影響圖像質(zhì)量。金屬偽影對后續(xù)圖像三維重建以及接觸面積的計算會產(chǎn)生直接或間接的影響,圖像中偽影的去除不可或缺。本文找到了一種基于K均值聚類與迭代修正的C T金屬偽影去除算法。首先,利用于K均值聚類法分割出金屬,并結合線性插值修正投影數(shù)據(jù),得到一張預處理圖像,接著以此為基礎進行迭代校正,迭代處理時通過各向異性平滑濾波來優(yōu)化圖像質(zhì)量,通過多次迭代后得到目標圖像。實驗表明,相比于傳統(tǒng)的分割和插值方法,本文方法能夠更加準確的分割出金屬物體和有效的去除金屬偽影,且不會引入新的條紋偽影。2.醫(yī)學圖像的三維重建:在對醫(yī)學圖像進行重建的過程中傳統(tǒng)三維面繪制移動立方體(M C)算法速度很緩慢、組織分離比較難,本文提出了一種改進的移動立方體算法。該算法根據(jù)人體器官相連的特征,首先挑選一些種子體元,然后依據(jù)這些種子衍生出器官全部等值面,從而減少了對沒用體元的搜尋;同時,通過n次等分點法代替線性插值求解法向量和等值點坐標,縮減了運算次數(shù)。提高了算法的執(zhí)行效率。重建出人工關節(jié)假體與宿主骨三維模型。為接觸面積的計算奠定基礎。3.接觸面積的計算:在三維重建模型的基礎上,通過結合有限元接觸分析理論和網(wǎng)格劃分軟件求出接觸面積。算法將建立好的三維模型以I G S格式導入到網(wǎng)格劃分軟件H y p e r m e s h 1 0.0中,對模型進行網(wǎng)格劃分。并在有限元接觸分析的基本理論上將假體和股骨接觸部分的網(wǎng)格節(jié)點一一對應,計算出網(wǎng)格的節(jié)點數(shù)和單元數(shù),進而估算出接觸面積。并通過對假體與宿主骨不同接觸區(qū)域面積大小的計算,討論接觸面積大小與松動的關系。具有較強的臨床意義和價值。
[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.
【學位授予單位】：河南科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：R687.4;TP391.41
本文編號：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.
【學位授予單位】：河南科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：R687.4;TP391.41
【參考文獻】
相關期刊論文 前1條
1 李鳴;;一種改進的各向異性擴散去噪算法[J];光電子技術;2014年01期
，本文編號：2239761
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