【摘要】 本文利用边界元方法计算了腹主动脉叉。在动脉粥样硬化前后的血液流场、血管壁切应力等血液流体动力学特性,通过对动脉粥样硬化产生前后,左、右髂总动脉壁切应力的计算结果分析,对粥样斑块病变产生和发展的血液流体动力学原因做出了判断。结果显示:腹主动脉叉几何形状的不对称性导致分叉处血液流速、血管壁切应力分布的不对称,内侧壁切应力大于外侧壁,右髂总动脉内侧壁切应力大于左髂总动脉。动脉粥样硬化处由于血管腔变窄血液流速明显变大、切应力变大,容易使斑块表面撕裂出现组织增生,粥样斑块下游处血流速度、切应力减小,形成血液分离区,使血细胞聚集,造成动脉粥样硬化发展、加剧。更多还原

【Abstract】 The hemodynamic characteristics of abdominal arterial bifurcation,such as blood flowing velocity vector,the shear stress at the vessel wall were calculated,studied and compared using the newly-induced boundary element method in this study.It was analysed why the atherosclerosis is asymmetrical at the bifurcation of abdominal arterial.The hemodynamic causes of production and development of the atherosclerotic were reasonabley explained by the shear stress calculation results of left and right common iliac branch vessel walls before and after the lesions.It is shown that the distribution of blood flowing velocity vector,the shear stress at the vessel wall are asymmetrical because of the asymmetrical geometry at the bifurcation of abdominal arterial,so that the shear stress of inner wall is higher than outside.The inner wall shear stress of right common iliac is higher than left.Blood velocity and shear stress increase at the atherosclerotic lesion because the blood vessel becomes narrower,and the blood velocity and shear stress decrease at the downstream of the lesion.It was also shown that the hemodynamic characteristics played a great important role in the occurrence and development of the atherosclerosis diseases at the bifurcation of abdominal arterial.Because of the increase of the shear stress,the atherosclerotic plaque surface will be damaged,leading to tissue hyperplasia.It will be lead to blood cell coacervation that the blood velocity and shear stress decrease at the atherosclerotic plaque downstream.更多还原