Analysis of mechanical performance of braided esophageal stent structure and its wires  

编织型食管支架结构及其丝线的力学性能分析(英文)

作　　者：倪晓宇[1] 王果[2] 龙志红[2] 潘长网 

机构地区：[1]南京林业大学机械电子工程学院,南京210037 [2]东南大学江苏省生物医疗器械设计与制造重点实验室,南京211189 [3]南京微创医学科技有限公司,南京210069

出　　处：《Journal of Southeast University(English Edition)》2012年第4期457-463,共7页东南大学学报（英文版）

基　　金：The National Natural Science Foundation of China(No.51005124);the Opening Foundation of Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments(No.JS-NB-2009-1-1)

摘　　要：This paper aims to find the relationship between the structural parameters and the radial stiffness of the braided stent and to understand the stress distribution law of the wires. According to the equation of the space spiral curve, a three-dimensional parametrical geometrical model is constructed. The finite element model is built by using the beam-beam contact elements and 3D beam elements. The constituent nitinol wires are assumed to be linear elastic material. The finite element analysis figures out that the radial stiffness of the stent and the stress distribution of the wires are influenced by all the structural parameters. The helix pitch of the wires is the most important factor. Under the condition of the same load and other structural parameters remaining unchanged, when the number of wires is 24, the stress of the wire crosssection is at the minimum. A comparison between the vitro experimental results and the analytical results is conducted, and the data is consistent, which proves that the current finite element model can be used to appropriately predict the mechanical performance of the braided esophageal stents.旨在找出支架结构参数与支架径向刚度之间的关系并了解支架变形及丝线上的应力分布规律.按照空间螺旋曲线方程创建几何模型,用梁-梁接触单元和三维梁单元建立有限元模型,并定义丝线为线弹性材料.有限元分析结果显示支架结构径向刚度及丝线上的应力分布与支架的各个结构参数都相关,其中丝线螺距对其影响最大.在相同载荷作用下,当丝线头数是24且支架的其他结构参数都不变时,丝线横截面上的应力最小.最后,将体外实验结果与分析结果进行比较,数据规律具有一致性,可以证明该有限元模型能够用于近似预测编织型食管支架的相关力学性能.

关 键 词：braided esophageal stent finite element mechanical performance radial stiffness WIRE 

分 类 号：R318[医药卫生—生物医学工程]