Stent Design And Biomechanical Analysis

Cardiovascular stents with various structures have been widely used to cure stenosis, but there are too many limitations for the existing stents, such as restenosis, and these issues have drawn much attention of researchers and clinician. From the perspective of designing stents structure, basing on the finite element analysis, the thesis studied the interaction between different types of stents (i.e., I-, C-, S-, U-, N- and W-types) and straight arteries, the interaction between stents and arteries of different curvatures (i.e.,0°,15°,30°,45° and 60°), and the interaction between stents and plaques of different shapes (symmetric and asymmetric) in the 60° curved artery. By comparing the results, it was shown that the stents could be optimized from several aspects.In the analysis between different stents and straight arteries, four indices including the maximum Mises stress and the maximum plastic strain of stents, the maximum Mises stress, and the expansion rate of arteries were evaluated, The results showed that S-type stent was superior to others in application of the straight artery.In the analysis between various stents and arteries with different curvatures, four indices including the maximum plastic strain of stents, the rate of the expansion, the maximum Mises stress, and the ellipticity of arteries were compared for all cases, and the tendencies of the four indices from I-type to W-type stent in different arteries were also examined. The results showed that S-type and U-type stents with larger plastic strain and lower Mises stress on the arteries provided the optimal outcome.In the analysis between stents and symmetric or asymmetric plaques in the 60° curved artery, the differences caused by the two plaques and S-type stent were compared, respectively, which indicated that different plaque models had a significant influence of the analysis. Besides, the interaction between the different stents and symmetric or asymmetric plaques were investigated separately. It also showed that the S-type stent with less influence on plaque and artery could be used for both plaque models.This paper optimized the stent structure through the stent-artery interaction analysis and stent-plaque interaction analysis, and could be useful for the commercial design and clinic selection of stents with different structures.