生物可降解镁合金支架的扩张性能

Expansion behaviour of biodegradable magnesium-alloy stent

介绍了生物可降解镁合金支架的应用背景和研究现状.应用有限元方法研究了镁合金支架的扩张过程.为了便于分析和比较,同时建立了具有相同几何模型的316L医用不锈钢支架,分别比较了它们在几何变形、应力分布、轴向缩短率、扩张速度等方面的差异性.结果显示,扩张镁合金支架比扩张不锈钢支架要容易得多.在扩张压力和扩张直径相同的前提下扩张镁合金支架和不锈钢支架,前者的扩张速度高于后者;前者的轴向缩短率小于后者;扩张到最大直径时,前者的最大Von M ises应力小于后者.有限元模拟对支架性能的评价和设计有一定指导意义.

The application background and research overview of biodegradable magnesium-alloy stem （BMS） are presented. A finite element modeling （FEM） was applied to study the expansion of BMS. A model of 316L stainless steel stent （SSS） with the same geometry parameter was also studied and mechanical parameters of both models were researched and compared, including geometry deformation, stress distribution, foreshortening and expansion velocity. The results show that BMS is much easier to expand than SSS. With same expanision pressure and expansion diameter, the expanding velocity of BMS is higher than that of SSS when expanded by balloon. Foreshortening of the former is smaller than that of the latter. Biggest Von Mises stress of BMS is lower than that of SSS when expanding to maximal diameter. In conclusion, FEM can quantify some mechanical behavior of stent and help designers to optimize stent system.