下肢动脉支架在多种变形模式下的力学性能对比研究

Comparative study on the mechanical properties of lower limb arterial stents under various deformation modes

下肢运动属于复杂且幅度较大的肢体运动,植入下肢的动脉支架易发生复杂的机械变形,因此要求下肢动脉支架具有较高的综合力学性能。为评价支架的力学性能,本文利用有限元法对6款镍钛合金下肢动脉支架(Absolute Pro、Complete SE、Lifestent、ProtégéEverFlex、Pulsar-35和New支架)在径向压缩、轴向压缩/拉伸、弯曲和扭转等不同变形模式下的力学性能进行数值模拟比较,并通过实验验证支架的径向支撑性能。研究结果发现,New支架综合性能优于其他支架,其中径向支撑性能优于Absolute Pro和Pulsar-35支架,轴向支撑性能优于Complete SE、Lifestent和ProtégéEverFlex支架,柔顺性能优于ProtégéEverFlex支架,扭转性能优于Complete SE、Lifestent和ProtégéEverFlex支架。通过TTR2型径向支撑力测试仪测试了6款支架的径向支撑性能,验证了有限元分析结果的正确性。本文揭示了支架结构尺寸对其多种变形模式下力学性能的影响规律,为临床应用中根据病变部位的需求选择合适的支架提供参考。

Lower extremity movement is a complex and large range of limb movement.Arterial stents implanted in lower extremity are prone to complex mechanical deformation,so the stent is required to have high comprehensive mechanical properties.In order to evaluate the mechanical property of different stents,in this paper,finite element method was used to simulate and compare the mechanical properties of six nitinol stents(Absolute Pro,Complete SE,Lifestent,ProtégéEverFlex,Pulsar-35 and New)under different deformation modes,such as radial compression,axial compression/tension,bending and torsion,and the radial support performance of the stents was verified by experiments.The results showed that the comprehensive performance of New stent was better than other stents.Among which the radial support performance was higher than Absolute Pro and Pulsar-35 stent,the axial support performance was better than Complete SE,Lifestent and ProtégéEverFlex stent,the flexibility was superior to ProtégéEverflex stent,and the torsion performance was better than Complete SE,Lifestent and ProtégéEverflex stent.The TTR2 type radial support force tester was used to test the radial support performance of 6 types,and the finite element analysis results were verified.The mechanical properties of the stent are closely related to the structural size.The result provides a reference for choosing a suitable stent according to the needs of the diseased location in clinical applications.