Surface Texture Design And Hemodynamic Simulation Analysis Of Vascular Stent

With the improvement of the quality of people’s life and the changes of lifestyle,cardiovascular disease has become one of the common diseases which does great harm to the health of human beings.Nowadays,vascular stent intervention therapy is the primar y method of clinical treatment of vascular stenosis,but the probability of postoperative vascular stent restenosis is still very high,so the performance optimization of vascular stent is particularly important.The design of imitation shark skin morphology on a vascular stent inner surface was optimized by simulation analysis,in order to optimize the distribution of intravascular hemodynamic parameters after vascular stent implantation,improve the blood flow features of the near-wall region of the stent,and reduce the incidence of restenosis in the stent.Firstly,according to the bionics principle,the bionic drag reduction morphology of the inner surface of the stent was abstracted into triangle and rectangle trench.In the groove structure parameters range from 0.025 mm to 0.06 mm,the two-dimensional simulation models of bionic surface texture vascular stents were built by ICEM CFD software.The effects of surface texture parameters on hemodynamics characteristics such as blood flow velocity,pressure and wall shear stress were analyzed by FLUENT software when the inlet blood flow velocity is constant.The optimal schemes were selected for the triangular and rectangular groove structure.Then,for further estimate two optimal structure,the fluid-solid coupling models of them were built by CAD software and Pro/E software.Using ANSYS Workbench 14.5,the blood flow characteristics in vascular stent,vascular deformation and stress distribution of stent were simulated and analyzed under the condition of the pulsating pressure at the inlet.The results show that the optimal design of surface texture improves the distribution of hemodynamic parameters in the vascular stent,which makes the whole blood flow more uniform,improves the blood flow velocity in the near-wall area,reduces the area of the shear stress area of the low wall,and reduces the maximum equivalent stress value of the vascular stent.To a certain extent,the probability of restenosis in vascular stent is reduced.When the width and the depth of a isosceles triangular groove are 0.04 mm,the vascular deformation is smallest,and the effect of comprehensive improvement is best.