血管支架柔顺性能的仿真模拟及灰色相关性分析

目的利用有限元法与灰色相关性理论的方法,分析并比较支架结构参数对支架植入后与血管同步运动能力的影响。方法选取S型闭环镁合金支架作为研究对象,应用Solid Works软件建立不同材料、周向支撑体数目、支撑体长度及初始直径共9款支架模型;应用Hyper Mesh软件进行支架模型网格的划分;应用ABAQUS软件模拟分析支架植入后与血管同步运动能力;利用灰色相关性理论研究并比较支架结构参数对弯曲刚度影响因子大小。结果材料对支架柔顺性的影响较明显,其中镁合金的柔顺性最好,对应弯曲刚度值为0.958 N·(rad·mm)~(-1);周向支撑体数目为5对应支架的柔顺性最好,其弯曲刚度值为0.853 N·(rad·mm)~(-1);支撑体长度为1.0 mm对应支架的柔顺性最好,其弯曲刚度值为0.829 N·(rad·mm)~(-1);初始直径为1.4 mm对应支架的柔顺性最好,其弯曲刚度值为1.024 N·(rad·mm)~(-1)。结论镁合金支架对应柔顺性最好,其次为不锈钢,钴铬合金支架对应柔顺性较差;柔顺性随着周向支撑体数目、支撑体长度、初始直径的增加而呈减小趋势变化;通过灰色相关性计算可知,材料对应柔顺性的影响最显著,其次为周向支撑体数目、支撑体长度,初始直径对其影响较小;分析支架结构参数对柔顺性的影响,可为支架的设计研发及临床治疗提供更加科学的参考。

Simulation on flexibility of the vascular stent and grey correlation analysis

Objective To analyze and compare the effects of structure parameters on synchronous motor ability between the blood vessel and stent after stent implantation by using finite element method and grey correlation theory. Methods The magnesium alloy stent of S closed-loop type was selected, and 9 models of such stents with different materials, numbers of support in circumferential direction, support lengths and initial diameters were established by using SolidWorks, and these stent models were meshed by using HyperMesh. The synchronous motor ability between the blood vessel and stent after stent implantation was simulated by using ABAQUS, and the influencing factors of different structure parameters on bending stiffness were investigated and compared by using grey correlation theory. Results The effect of materials on stent flexibility was obvious. The flexibility of magnesium alloy stent was the best, and the bending stiffness was 0.958 N?(rad?mm)-1; the best flexibility of stents were those with 5-support in circumferential direction, 1.0 mm-support length, and 1.4 mm-initial diameter, and their bending stiffness was 0.853,0.829 and 1.024 N?(rad?mm)-1, respectively. Conclusions The flexibility of magnesium alloy stent is the best, followed by stainless steel stent, and cobalt-chromium stent ranks last. With the increase of support numbers in circumferential direction, support length and initial diameter, the stent flexibility shows the decreasing tendency; the grey correlation analysis shows that the effect of materials on stent flexibility is the most significant, followed by support numbers in circumferential direction and support length, while initial diameter exerts the smallest influence. The analysis of structure parameter effects on stent flexibility will provide more scientific guidance for stent design and development as well as its intervention treatment in clinic.