Fluid-solid Coupling Simulation And Miocromechanical Properties Based On Rabbit Fusiform Aneurysm

Intracranial aneurysm is one of the most threatening diseases to human life and health among cerebrovascular diseases.The formation and development of intracranial aneurysm are closely related to its own hemodynamic performance and changes in the mechanical properties of the vascular wall.In recent years,computational fluid dynamics is mostly used to study intracranial aneurysms in numerical simulation,but the influence of vessel wall on aneurysms is neglected.Simple hemodynamic factors cannot truly reflect the change mechanism of aneurysms.In terms of mechanical properties experiments,the understanding of the mechanical properties of aneurysms remains at the macroscopic level,and little is known about the micromechanical properties of aneurysms.In this paper,based on the two-way fluid-solid coupling numerical simulation method,the pathological model of fusiform aneurysm was compared with the normal vessel,and the imaging data of the two were obtained to establish a finite element model.Then the data measured by intravascular ultrasound were used as the boundary conditions for the calculation of the numerical calculation.After the post-processing simulation results,the hemodynamic performance of the aneurysm and the aneurysm were calculated.The study of wall mechanical environment has certain data reference function.The Young's modulus of the adventitia of the fusiform aneurysm wall and the normal vessel wall were measured by atomic force microscopy indentation experiment to preliminarily understand the characteristic changes of micromechanical properties after aneurysm formation.The numerical simulation work based on imaging data proved that there were low WSS area and low blood flow turbulence area inside the aneurysm,especially the distribution of WSS size was basically similar to that of blood flow velocity,and there was no significant change in the blood flow of normal rabbits.The geometry of aneurysm will affect the stress release of blood and vessel wall.The geometric parameters such as neckwidth ratio and expansion ratio of fusiform aneurysm are directly related to the stress.At the same time,the potential location of aneurysm rupture is concentrated at the entrance of the aneurysm and the largest diameter of the aneurysm.Based on the atomic force microscopy indentation experiment,it was found that the Young's modulus of the adventitia of the aneurysm wall was higher than that of the normal vessel adventitia,especially the increase of the media was more obvious.The mechanical properties of the media and adventitia are interrelated and influence each other,and aneurysms are not as significant as normal vessels.In this paper,the hemodynamic performance of aneurysms and the mechanical environment characteristics of aneurysms were studied by means of numerical simulation based on bidirectional fluid-solid coupling,and the formation and development mechanism of aneurysms were explored by analyzing and comparing the changes of mechanical parameters between aneurysmal rabbits and normal vascular rabbits.Meanwhile,the micro-forces of aneurysm wall and normal vascular wall were also studied.Explore the nature of science.This provides a valuable data reference for the study of aneurysm wall biomechanical properties and the prevention and treatment of aneurysms.