Kiani M F, Hudetz A G
Department of Biomedical Engineering, Louisiana Tech University, Ruston 71272.
Biorheology. 1991;28(1-2):65-73. doi: 10.3233/bir-1991-281-207.
A semi-empirical model is developed to describe the dependence of apparent viscosity of blood on vessel diameter (2.7 to 500 microns) and vessel discharge hematocrit (5% to 60%). The blood flow is modeled as a cell-rich core and a cell-free marginal layer in the larger vessels and an axial-train in the smaller vessels. Laminar (Poiseuille) flow is assumed in all cases. An equation is derived in which apparent viscosity is a function of vessel diameter, core viscosity, and width of marginal layer. This is then complemented by empirical equations in which core viscosity varies exponentially with discharge hematocrit while the width of marginal layer varies linearly with discharge hematocrit. The model correlates well with several sets of experimental data and behaves according to the Fahraeus-Lindqvist effect. Predicted apparent viscosity tends to the expected finite value for large vessel diameters. Dependence of apparent viscosity on vessel diameter is realistically smooth in the whole diameter range.
开发了一个半经验模型来描述血液表观粘度对血管直径（2.7至500微米）和血管排出血细胞比容（5%至60%）的依赖性。在较大血管中，血流被建模为富含细胞的核心和无细胞边缘层，在较小血管中则为轴向排列。所有情况下均假定为层流（泊肃叶流）。推导了一个方程，其中表观粘度是血管直径、核心粘度和边缘层宽度的函数。然后通过经验方程进行补充，其中核心粘度随排出血细胞比容呈指数变化，而边缘层宽度随排出血细胞比容呈线性变化。该模型与几组实验数据具有良好的相关性，并且符合法赫瑞厄斯-林德奎斯特效应。对于大血管直径，预测的表观粘度趋向于预期的有限值。在整个直径范围内，表观粘度对血管直径的依赖性实际表现得很平滑。
