PRESSURE PROPAGATION IN PULSATILE FLOW-THROUGH RANDOM MICROVASCULAR NETWORKS

A microvascular network with random dimensions of vessels is built on the basis of statistical analysis of conjuctival beds reported in the literature. Our objective is to develop a direct method of evaluating the statistics of the pulsatile hydrodynamic field starting from a pri ori statistics which mimic the large-scale heterogeneity of the networ k. The model consists of a symmetric diverging-converging dentritic ne twork of ten levels of vessels, each level described by a truncated Ga ussian distribution of vessel diameters and lengths. In each vascular segment, the pressure distribution is given by a diffusion equation wi th random parameters, while the blood flow rate depends linearly on th e pressure gradient. The results are presented in terms of the mean va lue and standard deviation of the pressure and flow rate waveforms at two positions along the network. It is shown that the assumed statisti cal variation of vessel lengths results in flow rate deviations as hig h as 50 percent of the mean, while the corresponding effect of vessel diameter variation is much smaller. For a given pressure drop, the sta tistical variation of lengths increases the mean flow while the effect on the mean pressure distribution is negligible.