BLOOD FLOW IN VASCULAR TREES

还不可能确定组织的功能或 来自对单个微血管的详细观察的器官。在一个 努力了解组织的行为和反应是如何相关的 对微循环事件的研究一直很有兴趣 微血管网络。这项工作的一个主要目标是开发 微血管的计算机网络模型。这些型号包含了 有关网络拓扑、容器尺寸以及 细小管内血液流变学的特点。这些特点 包括Fahraeus效应(小孔内红细胞压积降低 管子)，Fahraeus-Lindqvist效应(较小的流动阻力 管子)和分叉处的等离子体掠过。尽管做出了这些努力，但仍有 仍然缺乏理论计算和理论计算之间的一致性 实验观察。 对这一建议的研究集中在对 血管网络中的分支模式，这在 以前的研究。将使用分枝树模式作为 网络的循环单元。序列分叉的产生 不同血液的浓度分布的扰动 成分(红细胞、白细胞、血小板和血浆)。这些 干扰可以向下传播到下一个分支，具体取决于 扰动的大小，交叉点之间的距离和 血液的速度。最新的实验和理论工作 血液在串联分支中的相分离允许包含 将这些现象转化为微血管网络模型。 这项研究将是对血液分布的计算研究 维管束树中的细胞。除了包括不对称的影响 浓度分布，这项研究也将检查影响 网络中分支的三维排列。的目标是 该项目将确定这些新概念是否会导致显著的 网络模拟计算结果的变化。基于 这项理论工作的结果，在动物身上的实验验证是 已经预料到了。

It has not been possible to determine the functioning of a tissue or organ from detailed observations of individual microvessels. In an effort to understand how the behavior and response of tissues are related to microcirculatory events, there has been great interest in studying microvessel networks. A major goal of this work has been to develop computer network models of the microvasculature. These models incorporate information on network topology, vessel dimensions as well as peculiarities of blood rheology in small tubes. These peculiarities include the Fahraeus effect (reduction in hematocrit in small bore tubes), Fahraeus-Lindqvist effect (lower resistance to flow in small tubes) and plasma skimming at bifurcations. Despite these efforts, there is still a lack of agreement between theoretical computations and experimental observations. The research of this proposal focuses attention on the serial nature of the branching pattern in vessel networks, which has been neglected in previous studies. A branching tree pattern will be used as a model of the recurring unit of the network. Serial bifurcations generate disturbances in the concentration profiles of the various blood components (red cell, white cells, platelets and plasma). These disturbances can be propagated downstream to the next branch depending on the magnitude of the disturbance, the distance between the junctions and the velocity of the blood. Recent experimental and theoretical work on phase separation of blood in serial bifurcations permit inclusion of these phenomena into microvessel network models. This research will be a computational study of the distribution of blood cells in a vascular tree. Besides including the effects of asymmetric concentration profiles, this study will also examine the influence of the three dimensional arrangement of the branches in a network. The goal of the project is to determine if these new concepts cause significant changes in the computational results of network simulation. Based on the results of this theoretical work, experimental verification in animals is anticipated.