WALL SHEAR STRESS IN THE CARDIOVASCULAR SYSTEM

心血管系统中的壁剪切应力

基本信息

批准号：
3349525
负责人：
JOHN M TARBELL
金额：
$ 9.08万
依托单位：
PENNSYLVANIA STATE UNIVERSITY, THE
依托单位国家：
美国
项目类别：
财政年份：
1985
资助国家：
美国
起止时间：
1985-12-01 至 1988-11-30
项目状态：
已结题

项目摘要

The shear stress of flowing blood on artery walls and the surfaces of prosthetic devices has a significant influence on the integrity of blood components, the coagulation of blood and formation of thrombi, the production of biochemicals by endothelial cells, the permeability of artery walls to macromolecules and the hydraulic resistance of artery walls to transmural water flux. Our knowledge of wall shear stress magnitudes and spatial variations in the circulation comes primarily from in vitro experiments in rigid models of arterial segments employing Newtonian blood analog fluids. Wall shear stresses have usually been estimated from velocity profile measurements in the near wall region, a method of questionable accuracy which cannot be employed with elastic models or in vivo. In the proposed research we will: 1. Further develop the technique of flush mounted hot film anemometry for application in pulsatile flows with reversal of wall shear stress direction. The proposed technique is based on a pulsed mode of anemometer bridge operation. 2. Determine experimentally the effect of elastic walls and non-Newtonian rheology on the spatial and temporal distribution of wall shear stress in pulsatile flows through curved artery models. We will measure wall shear stresses by flush mounted hot film anemometry techniques in pulsatile flows through both rigid and elastic curved artery models with glycerol/water and Separan/water solutions as well as blood. 3. Determine through numerical simulations the effect of elastic walls and non-Newtonian rheology on the fluid mechanics of pulsatile flows through curved artery models. We will first extend our rigid tube, Newtonian fluid simulations to include elastic walls. Ultimately we will include non-Newtonian rheology.

流动的血液对动脉壁和动脉表面的剪切应力假肢装置对血液的完整性有重大影响成分，血液凝固和血栓形成，内皮细胞产生生化物质，动脉的通透性血管壁对大分子的作用以及动脉壁对大分子的液压阻力跨壁水通量。我们对壁剪应力大小的了解和循环的空间变化主要来自体外使用牛顿血液在动脉段刚性模型中进行实验模拟流体。壁剪应力通常由以下公式估计近壁区域的速度剖面测量，一种方法准确性有问题，不能用于弹性模型或体内。在拟议的研究中，我们将： 1. 进一步发展嵌入式热膜风速仪技术在壁面剪应力反转的脉动流中的应用方向。所提出的技术基于风速计的脉冲模式桥接操作。 2. 通过实验确定弹性壁和非牛顿壁的效果流变学对壁面剪应力时空分布的影响通过弯曲动脉模型的脉动流。我们将测量墙剪力脉动流中齐平安装热膜风速测定技术的应力通过甘油/水的刚性和弹性弯曲动脉模型以及 Separan/水溶液以及血液。 3. 通过数值模拟确定弹性墙体的效果脉动流流体力学的非牛顿流变学弯曲动脉模型。我们将首先延伸我们的刚性管，牛顿流体模拟包括弹性墙。最终我们将包括非牛顿流变学。