FEM Calculation And Performance Analysis Of Vascular Stent Considering Polishing Effect

Coronary stents are generally tubular-shaped expandable devices which function to hold open a segment of a blood vessel. They are particularly suitable for use to support and hold back a dissected lumen. The stent implantation is now the favorable therapy to coronary heart disease, but the still higher restenosis with this device has become the main obstacle limiting the stent's further development. This dissertation obtains from the manufacture aspect, taking the stent polishing treatment's polishing quantity as the object of study, considered that the partial polishing effect of obvious parts, carries on the finite element analysis, obtains its polishing effect to the stent's expansion performance influence, then influences stent's restenosis.This dissertation introduces stent's domestic and foreign development process, present situation, research technique, and points out that carried on the analysis' superiority using the finite element method, proposes that this article used the finite element analysis' reason. Pointing out that the simulation of stent's geometrical parameter is established under the consideration of ideal design, it had not considered the stent's polishing process after manufacturing, and after the processing which geometrical shape can have a difference from the design, these differences will affect the stent's expansion.Secondly, this dissertation has analyzed the Teason which the polishing effect produces, as well as the geometry simulation of polishing effect, finally system analysis the two polishing effect to stent's expands influence. The result indicates: Only in the middle connection of stent's polishing, its polishing quantity smaller, expands rapidly the load fill-out, this time expands the displacement quantity to be smaller, but when expands, the biggest radial displacement is bigger; Only in the sides of stent's polishing, the much stent's polishing quantity, the bigger it's rapid expansion load, the process will appear moves the non-uniform change, but at last the expansion of the radial displacement is bigger.Finally, this dissertation proposes the concept of heterogeneous rate, gives the quantitative analysis to stent's expansion of heterogeneity, shows that the explanation polishing effect have an very important influence to stent's heterogeneous rate.