Coronary Stent Mechanical Properties Analysis And Structure Optimization Research

Stent intervention surgery is to implant a vascular stent into a narrow blood vessel,then applying a forced load to prop up the stent and eventually the stent supports the vessel based on its own material properties.This article introduces the mechanical analysis of the stent,including the finite element simulation of the stent in vivo and the finite element simulation of the stent in vitro test.In this paper,the structural parameters of scaffolds were optimized in vivo simulation and compared with in vitro experimental simulation.Finally,experiments were carried out to verify the scientificity of the simulation.In order to achieve the goal,the following aspects were mainly carried out:1.Analysis and simulation of mechanical properties of scaffoldsThe in-vitro and in-vitro finite element simulations of the stent were considered respectively.The in-vitro test finite element simulation process established an integrated model of the bare stent model and the addition of balloons and compression grip shells.The bare stent model is applied forced displacement on the stent,The integrated model is applied a forced load on the balloon and the pressure grip shell,and the stress situation and various mechanical performance indicators of the stent under the two model systems are simulated,At the same time,an in vitro test will be conducted to compare the test results and verify the scientificity of the integrated modeling method;The vascular plaque stent model was established by finite element simulation in vivo,and the working state of the stent was simulated under the stenosis of vessels in vivo.The influence of stent performance and stent on vascular stress was analyzed,and the influence of stent on vascular wall stress was observed at different stenosis rates,so as to provide a basis for subsequent optimization.2.Analysis of the influence of stent structural parameters on the stress of narrow vesselsSupport body and link is composed of a support structure of two parts,that support bracket and connect for stent,this article established three different connection forms of I-type,C-type and S-type and three different bracket thicknesses of 0.05 mm,0.08 mm and 0.11 mm,the link form and thickness as variables,The maximum stress level on the surface of the blood vessel wall as the sole criterion for the stent expansion process,Obtaining a C-type stent causes the maximum stress on the surface of the blood vessel wall to be small,The smaller the thickness of the stent,the smaller the maximum stress on the surface of the vessel wall,Therefore,the optimal C-h5 support model is obtained.3.Analysis of the influence of scaffold thickness on its biomechanical propertiesIn vitro finite element simulation was carried out on scaffolds of three thicknesses to investigate the effects on the biomechanical properties of scaffolds.Compared with the target parameters of the expansion process,the scaffolds with a thickness of 0.05 mm had better performance,which was consistent with the results of in vivo finite element simulation.4.Comparison of in vitro test data and simulation results of optimized stentThe optimized C-h5 stent and the preliminary optimized C-H10C7 stent were tested in vitro.Compare the simulation results of expansion performance and radial compression performance with the test.Verify that in vitro testing is consistent with in vivo simulation conclusions.