PULMONARY INTERSTITIAL MECHANICS

肺间质是一条引流微血管的通路。 从肺中滤出。因此，它的属性对于 了解如何维持正常的体液平衡，以及 肺水肿的发病机制。几种机械力可能具有 在测定肺间质液压力中的重要作用。 这种力包括作用于血液外部的实质应力。 作用于肺泡壁的血管和支气管、肺泡表面张力 以及间质内流体流动产生的粘性力。这 Project将更精确地量化这些力量，以努力 了解肺水肿形成的机制。这个 重点放在三个相关领域：间质的直接测量 电导率--间质和肺泡液的直接测量 压力，以及作为以下函数的肺应力波测量 浮肿的形成。一种分离短长度肺脏的方法 硅橡胶之间保持固定的间隙被开发来研究 大肺周围间质的压力-流动行为 血管和间质流体的传导性。水合作用的影响， 蛋白质浓度、液体粘度、电荷和 测定透明质酸酶对间质电导率的影响。达西定律 对于一种可渗透的材料，被用来量化 间质组织。然而，初步研究表明，一种蛋白质 间质中的浓度梯度。目标是建立 肺间质蛋白质筛选的重要性。因此， 有效反射系数和渗透率表面积 间质对蛋白质流动的产物将在 间质节段。蛋白质浓度的纵向梯度 会测量充气液体中间质袖带的生长情况 肺部。肺泡水肿胀形成对肺泡液体压的影响 在完好的兔子身上进行测量。这些研究将确立 肺泡表面张力对肺泡液体平衡和肺功能的影响 将测试之前在隔离肺中进行的测量的有效性。 对离体肺和完整胸腔的应力波研究表明 产生和测量这些波作为指标的可行性 肺水肿形成的可能性。用于产生和检测的方法 来自胸部表面的肺应力波将在完整的情况下形成 猪的实验。长期目标是开发一种非侵入性方法 用于检测临床肺水肿。

The pulmonary interstitium is a pathway which drains microvascular filtrate from the lung. Thus its properties are important to the understanding how normal fluid balance is maintained and of the pathogenesis of pulmonary edema. Several mechanical forces may have an important role in determining pulmonary interstitial fluid pressure. Such forces include the parenchymal stress acting on the outside of blood vessels and bronchi, alveolar surface tension acting on alveolar walls and viscous forces arising from fluid flow within the interstitium. This project will quantify these forces more precisely in an effort to understand the mechanisms underlying pulmonary edema formation. The focus is on three related areas: the direct measurement of interstitial conductivity, the direct measurement of interstitial and alveolar liquid pressures, and the measurement of lung stress waves as a function of edema formation. A method of isolating a short length of pulmonary interstitium held fixed between silicon rubber was developed to study the pressure-flow behavior of the interstitium surrounding large pulmonary vessels and interstitial fluid conductivity. The effects of hydration, protein concentration, fluid viscosity, electric charge, and hyaluronidase on interstitial conductivity were determined. Darcy's law for a permeable material was used to quantify the fluid properties of the interstitial tissue. However, preliminary studies indicated a protein concentration gradient in the interstitium. The goal is to establish the importance of protein sieving in pulmonary interstitium. Accordingly, the effective reflection coefficient and permeability-surface area product of the interstitium to the flow of protein will be measured in interstitial segments. Longitudinal gradients in protein concentration will be measured during interstitial cuff growth in liquid inflated lungs. The effect of edema formation on alveolar liquid pressure will be measured in intact rabbits. These studies will establish the importance of alveolar surface tension on alveolar liquid balance and will test the validity of previous measurements made in isolated lungs. Stress wave studies in isolated lungs and in the intact chest have shown the feasibility of generating and measuring these waves as an indicator of pulmonary edema formation. Methods for the generation and detector of lung stress waves from the chest surface will be developed in intact pig experiments. The long term goal is to develop a noninvasive method for detecting clinical pulmonary edema.