Simulation Analysis On The Influence Of Micro Texture Morphology Characteristics On Blood Flow Characteristics Of Vascular Stent

In recent years,the incidence of cardiovascular diseases has been increasing with dietary structure and lifestyle changes of people.Because of the advantages of safe operation,low surgical trauma,high success rate and few complications,vascular stenting intervention has become the preferred treatment for cardiovascular diseases.However,the high incidence of restenosis after stenting has affected the therapeutic effect of stenting to some extent.A number of studies have shown that the causes of restenosis include poor lifestyle habits,excessive intimal hyperplasia,inflammatory reactions,and changes in hemodynamic parameters.Among them,blood flow rate among hemodynamic parameters is the main factor affecting restenosis in vascular stents.A slow blood flow rate tends to lead to the deposition of lipids and proteins in the blood on the vessel wall blocking the vessel and increasing the risk of restenosis.Therefore,it is important to analyze and study the characteristics of hemodynamic parameters and their patterns after the stent is placed in the blood vessel,so that it can be functionally regulated to adapt to the normal physiological needs of the human body,which can slow down and reduce the probability of restenosis to a certain extent.It was found that the surface microweave has a good barrier-reducing and anti-adhesive effect,and this property provides a new idea for the improvement of vascular stents.Based on this,the paper investigates the design of ortho-hexagonal microweave on the inner wall surface of vascular stents and analyzes the effect of microweave with different morphology and parameters on blood flow characteristics.The specific research of this paper is as follows:(1)By analyzing and summarizing a large number of literatures on micro texture,the types and parameters of micro texture are determined.Type of micro texture: regular hexagonal pit micro texture and regular hexagonal convex micro texture.The area share of micro texture is 11.2%,20.4% and 31.9% respectively.The depth(height)of micro texture is 30μm,35μm,40μm,45μm and 50μm.(2)The hexagonal concave and convex micro textured tubular stent models with different area occupancy and depth(height)were established to explore the effects of different textural parameters on blood flow in a cardiac cycle,and analyze the blood flow velocity,distribution and blood flow near the wall in different stent cavities at peak and stable times.(3)The fluid solid coupling models of non-textured reticular stent,hexagonal concave textured reticular stent and hexagonal convex textured reticular stent with blood and blood vessels were established.Explore the blood flow state,vascular deformation and stress of stents in different vascular stents in a cardiac cycle,and analyze the effect of different micro textures.The results show that reasonable micro texture morphology and parameters can improve the blood flow speed and blood distribution.The area occupancy,depth /height,type and arrangement of micro texture will affect the blood flow characteristics.The regular hexagonal convex micro texture with a height of 45μm and an area occupation rate of 31.9% has the greatest influence on the blood flow state.