Simulation of particle-hemodynamics in a partially occluded artery segment with implications to the initiation of microemboli and secondary stenoses
Simulation of particle-hemodynamics in a partially occluded artery segment with implications to the initiation of microemboli and secondary stenoses
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DOI：
10.1115/1.2798013
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发表时间：
1998-08-01
影响因子：
1.7
通讯作者：
Kleinstreuer, C
中科院分区：
文献类型：
--
作者：
Buchanan, JR;Kleinstreuer, C
本文给出了在局部光滑收缩率为75%的轴对称动脉段中层流不可压缩血液-颗粒流分析的计算结果。流量输入波形为正弦曲线，平均值为非零。用改进的Quemada模型模拟血液的非牛顿行为，用漂移通量模型计算血小板浓度，描述单核细胞轨迹并比较牛顿和Quemada流变学。“扰动流”的指标包括时间平均壁面剪切应力（WSS）、振荡剪切指数（OSI）和壁面剪切应力梯度（WSSG）。原发性狭窄后的涡流模式对微栓子形成和下游狭窄的影响如下。由于再循环区中的聚集而导致的血小板浓度升高，与假定在高壁剪切应力区域中向上游释放的凝血酶和ADP复合物混合，可能形成微栓子，微栓子向下游对流。引起WSSG和OSI局部增加的明显近壁涡流以及可能存在壁沉积的血液颗粒夹带，表明在初始几何扰动近端易发生额外狭窄的部位。
Computational results of laminar incompressible blood-particle flow analyses in an axisymmetric artery segment with a smooth local area constriction of 75 percent have been presented. The flow input waveform was sinusoidal with a nonzero average. The non-Newtonian behavior of blood was simulated with a modified Quemada model, platelet concentrations were calculated with a drift-flux model, and monocyte trajectories were described and compared for both Newtonian and Quemada rheologies. Indicators of ''disturbed flow'' included the time-averaged wall shear stress (WSS), the oscillatory shear index (OSI), and the wall shear stress gradient (WSSG). Implications of the vortical flow patterns behind the primary stenosis to the formation of microemboli and downstream stenoses are as follows. Elevated platelet concentrations due to accumulation in recirculation zones mixed with thrombin and ADP complexes assumed to be released upstream in high wall shear stress regions, could form microemboli, which are convected downstream. Distinct near-wall vortices causing a local increase in the WSSG and OSI as well as blood-particle entrainment with possible wall deposition, indicate sites susceptible to the onset of an additional stenosis proximal to the initial geometric disturbance.