基于SimVascular的腹主动脉复杂模型构建与血流动力学仿真研究

A Simulation Study on Hemodynamics and Complex Structure Modal Construction of Abdominal Aorta Based on SimVascular

研究在不同入口血流速度下,仿真计算逼近人体腹主动脉和髂动脉及其分支形状的血流动力学参数的变化情况。依据获取的CT血管数据,采用开源SimVascular软件构建腹主动脉以及附近主要动脉的血管模型,具体包括腹主动脉干、腹腔动脉、脾动脉及其分支肝动脉,肠系膜上下动脉及其分支,左右髂动脉及其分支和左右肾动脉。通过Fluent进行仿真计算,主要分析人体血管各处的血流速度矢量、静态压力和剪切力的血流动力学表现。在入口处施加不同的速度载荷条件,分别定义收缩期的类抛物线函数速度和平均定值速度,发现在这两种条件下,血管在分叉和小直径血管处,都出现较大速度和剪切力。但是在肠系膜上动脉和左右髂动脉的远端出现明显的不同。同时还发现入口速度的逐渐增加,会加倍血管各分叉处的血流速度。总之,成功构建复杂血管网络并进行仿真计算,将有助于医生更深入理解动脉血流力学特征。

This paper studies the simulation calculation for the variation of hemodynamics parameters in human abdominal aorta and iliac artery under different blood flow velocities at the entries.And it adopts open source software SimVascular to construct the vessel models of abdominal aorta and some major arteries nearby including celiac axis,celiac artery,splenic artery and its hepatic artery branches,superior and inferior mesenteric arteries, left and right renal arteries and iliac arteries according to the CT vessel data.Besides,this paper mainly analyzes the blood velocity vector,static pressure,and wall shear stress by using the Fluent simulation calculation.Finally, the quasi-parabolic-like function velocity and the average constant velocity were assigned at the entry respectively, and it was found that in both conditions,the arterial models appeared larger velocities and wall shear stresses at the bifurcation and small- diameter vessels.However,there were significant differences between the superior mesenteric artery and the distal end of the left and right iliac arteries.At the same time,it was also found that the gradual increase in the entry speed would double the speed of the bifurcation artery.In conclusion,the successful construction of complex arterial networks and the results of simulation will help doctors better understand the characteristics of arterial blood flow.