Ye G F, Moore T W, Jaron D
Biomedical Engineering and Science Institute, Drexel University, Philadelphia, PA 19104.
Ann Biomed Eng. 1993 Mar-Apr;21(2):97-106. doi: 10.1007/BF02367605.
A popular and useful technique used to model blood flow in cardiovascular simulations is to divide each blood vessel into a series of segments, each with its own lumped resistance, inertance, and compliance parameters. The values of these parameters are usually obtained through a simplification of the Navier-Stokes equations for fluid flow. However, the simplification often ignores the nonlinear and convective terms of the equations, resulting in errors in the parameter values, especially in the value found for resistance per unit length. We report a new method for the calculation of vessel resistance per unit length which takes into account the effects of vessel taper and wall compliance. It is shown that these effects can be addressed by the addition of two time-varying terms to the calculation of resistance per unit length. One term, due to vessel taper, is proportional to volumetric flow rate Q. The other term, due to vessel compliance, is proportional to delta p/delta t. These variables are readily available in computer simulations of blood flow in lumped parameter systems. Using data for the descending aorta, the new parameter values, when averaged over a cardiac cycle, compare favorably with results in the literature.
在心血管模拟中，一种常用且流行的模拟血流的技术是将每条血管划分为一系列节段，每个节段都有其自身的集总电阻、惯性和顺应性参数。这些参数的值通常通过对流体流动的纳维-斯托克斯方程进行简化得到。然而，这种简化通常忽略了方程的非线性和对流项，导致参数值出现误差，尤其是单位长度电阻的值。我们报告了一种计算单位长度血管阻力的新方法，该方法考虑了血管锥度和壁顺应性的影响。结果表明，通过在单位长度电阻的计算中添加两个随时间变化的项，可以解决这些影响。一项由于血管锥度，与体积流量Q成正比。另一项由于血管顺应性，与Δp/Δt成正比。这些变量在集总参数系统中血流的计算机模拟中很容易获得。使用降主动脉的数据，新的参数值在一个心动周期内平均后，与文献中的结果相比具有优势。
