Effects of stent structure on stent flexibility measurements
Effects of stent structure on stent flexibility measurements
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DOI：
10.1007/s10439-005-2807-6
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发表时间：
2005-06-01
影响因子：
3.8
通讯作者：
Saito, T
中科院分区：
文献类型：
--
作者：
Mori, K;Saito, T
冠状动脉内支架的适当运送和放置取决于支架本身的各种特性，包括柔韧性和高径向强度。虽然这些特性可以通过确定支架的弯曲刚度和径向刚度来评估，但支架的网状结构不容易进行此类测量。本研究的目的是确定确定支架弯曲刚度的最佳方法。采用四点弯曲试验评价支架柔韧性，采用有限元法评价不同连接结构的支架结构对支架柔韧性的影响。四点弯曲试验得到的抗弯刚度值为：s形连杆支架的抗弯刚度为85.28 N mm(2)；N型连杆支架41.67 N mm(2)；78.79 N mm(2)：带有改良w型连杆的支架；w型连杆支架188.67 N mm(2)。采用点对称连杆构型（S型、N型和修改后的w型连杆）的支架具有较高的柔韧性。有限元分析表明，低柔度是由受压侧支板之间的干涉造成的。此外，从有限元分析中预测的柔性与支架的弯曲刚度相关。我们得出的结论是，使用四点弯曲试验产生的信息是至关重要的柔性支架的设计。
Adequate delivery and placement of intracoronary artery stents is dependent on various properties of the stent itself, including flexibility and high-radial strength. Although these properties can be assessed via determination of the bending stiffness and radial stiffness of a stent, the mesh structure of the stent does not lend easily to such measurements. The goal of the present study was to determine an optimal method for determining stent bending stiffness. The four-points bending test was used to evaluate stent flexibility, and the finite element method (FEM) was employed to assess the effect of stent structure on flexibility in stents with differing link structures. The four-points bending test yielded the following bending stiffness values: 85.28 N mm(2) for the stent with an S-shaped link; 41.67 N mm(2) for the stent with an N-shaped link; 78.79 N mm(2) for the stent with a modified W-shaped link; and 188.67 N mm(2) for the stent with a W-shaped link. The stent with the point symmetric link configuration (S-, N- and modified W-shaped link) had high flexibility. FEM analysis revealed that low flexibility resulted from interference between the struts at the compressive side. Further, the flexibility predicted from FEM analysis correlated with bending stiffness of the stents. We conclude that use of the four-points bending test yields information that is critical for the design of flexible stents.