Biomechanics Research Of A Novel Cardiovascular Stent

By means of groove design on the outside surface of drug eluting stent(DES),the drug can release from the grooves on the outside surface directly,to achieve the goal of "targeted therapy".This method can reduce effectively the side effects to normal tissues because of drug release.Because the drop of the mechanical properties may occur,structure optimization design of the stent is needed in order to ensure the safety and effectiveness of the stent.In this thesis,the biomechanical property of traditional drug eluting stent and the targeted drug eluting stent was researched detailedly.The main content of this research is as follows.First,two stent models with different structures were set up using the software of Solidworks,which were traditional drug eluting stent and targeted drug eluting stent.The stent models were meshed and optimized using the software of Hypermesh.Second,the biomechanical properties of the two kind of stents were studied using the finite element analysis software named Abaqus.The radial compression performance,radial expansion performance,fatigue performance,conform performance,and radial support performance were analyzed.The results prove that,compared with the traditional DES,rebound ratio of radial contraction,rebound ratio of axial contraction,inhomogeneity of compression,rebound ratio of radial direction,rebound ratio of axial direction and the inhomogeneity of expansion and radial support stiffness of the targeted DES didn't reduce.With the same stent materials,targeted DES was more easily to be compressed and expanded.Besides,the targeted DES could meet the requirements of fatigue strength and had a higher sensitivity.Third,the grooves of the targeted DES were designed optimally.In order to compare the influence of the different groove size to the mechanical behavior of stents,nine stent models with different groove sizes were set up.Using the software named Abaqus,the influence of the groove size to the radial compression performance,radial expansion performance,fatigue performance,conform performance,and radial support performance were analyzed.The results proved that,the influence of the different groove size to the radial compression performance and radial expansion performance was very small,while the fatigue performance,conform performance and radial support performance were affected greatly.Overall consideration,the stent(whose groove size are: length=0.4mm,width=0.025 mm,depth=0.05mm)hasthe optimal combination property.