Numerical Simulation Of Lenticular Artery Hemorrhage Based On Arteriovenous Network Model

Stroke is considered to be one of the fatal diseases only after tumor and heart disease.It is due to the obstruction of some part of the blood vessels in the brain,which causes the blood of the arteries to not flow normally into the key parts of the brain,or the disease caused by the sudden rupture of the blood vessels in some part of the brain which causes the blood flow out and the brain tissue damage.Stroke mainly includes ischemic stroke and hemorrhagic stroke.The main characteristic of cerebral hemorrhage is to mean intracerebral hemorrhage in the case of non trauma.The proportion of cerebral apoplexy is about 20%~30%,which is characterized by high incidence,rapid progress,disability and high mortality.A large number of studies have shown that most of the bleeding sites are located in the basal nucleus,that is,the terminal of the lenticulostriate artery,which accounts for about 91% of the bleeding site,so the lenticulostriate artery has become the focus of attention of scholars.In this paper,the bean stripe artery is the main object of study.First,establish an arteriovenous model including lenticulostriate artery,capillaries and veins.The traditional model set the arterial end as the exit boundary of blood flow,ignoring the effect of capillaries on arteries.In order to make the numerical simulation more practical,it is necessary to model the capillaries at the end of the lenticulostriate artery.However,the size of the capillaries in the basal nuclei is too small and the geometric modeling can not be realized.Therefore,the porous media is introduced to replace the capillaries in the hemodynamics,and the bean striate artery is connected with the vein to establish a complete fluid-solid coupling model of the arteriovenous network.According to the actual condition of the brain,the parameters and boundary conditions of the model were set up,and several main factors causing the rupture of the lenticulostriate artery were analyzed.Second,hypertension is an important factor in cerebral hemorrhage,which accounts for the largest proportion in cerebral hemorrhage.The effect of hypertension on the rupture of the lenticulostriate artery was simulated by setting up the boundary conditions of different levels of hypertension.The relationship between hypertension and the rupture of the lenticulostriate artery was discussed,and the blood pressure and the stress curve of the blood vessel were obtained.Third,microcirculatory disturbance is also an important factor leading to rupture ofthe lenticulostriate artery.In this paper,the influence of microcirculatory disturbance on the rupture of the lenticulostriate artery was simulated by gradually reducing the permeability of porous media to keep the other parameters and boundary conditions constant.The effects of microcirculation disturbance on the blood pressure and vascular wall stress of the lenticulostriate artery were analyzed.Fourth,the effect of venous return disturbance on the lenticulostriate artery is not negligible.As people are stimulated by external stimuli or under the compression of the jugular vein,the blood pressure of the brain is increased.Therefore,in the vascular network model,the venous reflux disorder is simulated by gradually increasing the venous blood pressure,and the effects of venous reflux on the blood pressure of the lenticulostriate artery and the stress of the vascular wall are analyzed.Fifth,anatomical studies revealed that there were also ruptures at the initial end of the lenticulostriate artery.Most of the lenticulostriate arteries are almost perpendicular to the middle of the middle artery,and scholars believe that this special configuration can change the direction of the blood flow quickly and supply blood to the basal nucleus of the brain.However,the change of blood flow direction causes the shear stress concentration at the initial end of the lenticulostriate artery,resulting in rupture.In order to prove that the rupture of the starting end of the lenticulostriate artery is related to its configuration,three different configurations of the model of the lenticulostriate artery were established in this paper,and the numerical simulation and analysis were carried out in the same condition and the parameters of other boundary conditions.