The Application Of The Hemodynamic Analysis In The Research Of Post-stroke Microcirculation

Stroke is one of the most common causes of death with high incidence,mortality and morbidity.Pathology of stroke is already well known.The studies of targeted prevention and treatment have been rapidly developed in recent years.The reduction of blood perfusion in brain induced by stroke can cause self-regulation and remodeling of cerebral circulation.In order to study the influences of the structure of cerebral vasculature on the hemodynamic characteristics,2D cerebral microvascular networks based on continuous and discrete modeling were established in the thesis.Blood perfusion simulation and hemodynamic analysis were further conducted through the micro vessels.The thesis was divided into five sections.In the first part,methodology of the 2D cerebral microvascular mathematical model on the basis of continuous and discrete mathematical equations was presented.The second part illuminated the iterative numerical solution method of hemodynamic analysis coupling with vascular compliance and blood rheology.In the third part,we performed simulations of vascular infarction under different conditions and quantified the influence of vascular network density on the blood perfusion.In the fourth part,self-regulation and the remodeling of cerebral microcirculation after the stroke was studied.The final part mainly focused on quantifying the compensatory function of collateral circulation and the changes of vascular density after remodeling.In order to present the simulation results more intuitively,blood flow change rate(BFCR)was proposed to measure the changes of blood flow.The results of simulation showed that the high density of vascular network resulted in a small BFCR.The infracted vessel could cause a great BFCR.Meanwhile,the degree of ischemia was related to the scale of the infarcted vessel.Cerebral vessels can automatically self-expand to alleviate ischemia of tissue when infarction is not serious.However,when vessel infarcts seriously,the ability of self-regulation is limited and vascular remodeling is activated,which can be demonstrated by the distinct statistical increase of vascular density in ischemic region.Additionally,by quantitatively analyzing the data,it is found that the greater vascular network density is,the larger the scope of microcirculation network is perfused by collateral circulation.With the increase of infarction degree,blood perfusion of collateral compensatory quantity also increases.While,when vessel infarcts seriously,compensatory perfusion amount is decreased as the degree of infarction increasing.The results are consistent with clinical studies.