红细胞非惯性升力对血液流动的影响

Effects from non-inertial lift of red blood cells on blood flow

目的 为准确模拟血流，研究红细胞变形性对血液流动的影响。方法 基于血液流变特性和红细胞力学特性分析，对现有血液两相流流动模型进行改进，改进模型中考虑了易变形红细胞受剪切流场或血管壁面作用而产生的非惯性升力的影响。利用改进模型对多个不同直径血管内的血液流动进行模拟。结果 由红细胞所受非惯性升力导致的径向运动对血管内红细胞体积分数、运动速度分布有明显影响；当血管直径为0.1-3.0 mm时，用改进模型得到的血液相对黏度的模拟值与测量值接近。结论 非惯性升力是血流呈现Fahraeus-Lindqvist效应的主要原因之一。考虑非惯性升力的改进模型可以准确模拟血液流动，为循环系统诊疗机制和细胞分选等过程的模拟提供更为准确的方法。

Objective To study the influence of red blood cell （RBC） deformability on blood flow, so as to make the blood flow simulation more accurately. Methods Based on analysis of rheological properties of blood and mechanical properties of RBCs, the existing two-phase flow model of blood was improved, and the effect of non-inertial lift force generated by the interaction between soft RBCs and shear flow or the vessel wall was considered in the improved model. The blood flow in vessels with different diameters was simulated by using this improved model. Results The radial motion of RBCs generated by non-inertial lift force had an obvious influence on the distribution of RBC volume fractions and blood velocity. When the vessel diameter was between 0.1-3.0 mm, the simulated relative viscosity of blood by the improved model was very close to the measured viscosity. Conclusions The non-inertial lift force is one of the main reasons leading to Fahraeus-Lindqvist effect of blood, and the improved model considering the non-inertial lift force can simulate the blood flow more accurately, which provides a more accurate method for the simulation of vascular system treatment and cell sorting.