The Plastic Deformation and Stress Distribution of Stent in the Artery

• Main Authors: Yung-yu Chen, 陳勇諭
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/50794060553467999300

碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 94 === The plastic deformation of stent during the implantation process, with considering the effect of artery and plaque, was investigated in this thesis. The stress-stretch relationships of porcine coronary arteries and aortas were obtained by the tensile test. The nonlinear ABAQUS finite element software was used in the analysis. The nonlinear-elastic, plastic and linear elastic material models for artery-plaque, stent and balloon were employed respectively. In this thesis, the initial folded balloon model was proposed to simulate the whole inflation and deflation process of balloon deformation. To investigate the effect of artery with plaque on the deformation of stent, the FEM model with considering the artery and plaque was proposed to simulate the expansion process of stents. The plaque’s destruction during the expansion of stent was studied. The effects of plaque’s thickness and the artery models on the expansion of stent were investigated. The effects of geometrical parameters and the influences on the deformation and the stress distribution of Palmaz type stent were discussed. The expansion ability and foreshortening of Chen and Tsai’s stent were also assessed in this work. The results indicate that the limited expansion ability make Chen and Tsai’s stent be not suitable for using as coronary stent. It might be used as the stent of carotid artery if its expansion ability improved by properly designing stent’s diameter and geometry shape. The results reveal the foreshortening of Chen and Tsai’s stent does not approach to zero as mentioned by Chen. A Chen modified and Tsai’s stent was also proposed in this study. The simulation results show that the foreshortening in the Chen modified type is improved.