冠状毛细血管长度非线性变化及渗透作用下的毛细血管血液流动

Blood Flow in a Coronary Capillary Considering Influence of Vessel Nonlinear Length Change and Infiltration

建立冠状毛细血管内血流的血液动力学模型,研究毛细血管长度沿轴向的非线性变化及冠状毛细血管与周围组织的渗透和物质交换对血液流动的影响。考虑单根长弹性并具有通透性的冠状毛细血管,毛细血管长度非线性变化,毛细血管内血液为粘性不可压缩牛顿流体,跨壁滤过遵循Starling定律,血浆胶体渗透压和血浆蛋白浓度成线性关系。建立血管半径的无量纲方程,数值求解不同生理参数情况下,左心室壁不同层中毛细血管沿长度平均的无量纲半径和不同层毛细血管的平均流量。结果显示,冠状毛细血管与周围组织的渗透和物质交换及毛细血管长度沿轴向的非线性变化对平均无量纲半径和平均出口流量几乎没有影响;而对弹性模量较小的毛细血管,则对心脏收缩期时的平均进口流量有不同程度的影响。

A hemodynamics model of blood flow in a coronary capillary has been presented, allowed for the axial nonlinear length change of the capillary, as well as the infiltration and materials exchange between capillaries and tissues. A single, long, elastic and permeable coronary capillary is considered. The length change of the capillary is linear, the blood in the capillary is regarded as viscous incompressible Newtonian fluid. The infiltration obeys the Starling Law, the plasma colloid infiltrative pressure owns a linear relationship with plasma protein concentration. The established dimensionless equations about the vessel's radius are numerically solved. The average dimensionless radius along the coronary capillary in the different layers of left ventricular wall and the average of flows in the different layers are investigated in the different physiological parameters. The results show that the influences of the infiltration and material exchange between capillary and tissue as well as the axial nonlinear length change of the capillary to the average dimensionless radius and the average outflow can be almost neglected; But as the vessel's elasticity modulus is small, the influences to the average inflow are different.