WALL SHEAR STRESS IN THE CARDIOVASCULAR SYSTEM

心血管系统中的壁剪切应力

• 批准号: 3349524
• 负责人: JOHN M TARBELL
• 金额: $ 10.54万
• 依托单位: PENNSYLVANIA STATE UNIVERSITY, THE
• 依托单位国家: 美国
• 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
• 来源: https://reporter.nih.gov/project-details/3349524
• 关键词: atherosclerosis; blood vessels; elasticity; hemodynamics; mathematical model; mechanical stress; model design /development; vascular endothelium

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.

在动脉壁上流动血液的剪切应力和 假体设备对血液的完整性有重大影响 成分，血液的凝结和血栓形成， 由内皮细胞生产生化物，动脉的渗透性 大分子的墙壁和动脉壁的液压抗性 透壁水通量。 我们对墙剪切应力的了解和 循环的空间变化主要来自体外 采用牛顿血液的动脉片段刚性模型的实验 模拟流体。 通常从 近壁区域中的速度剖面测量值 弹性模型或中不能使用的可疑精度 体内。 在拟议的研究中，我们将： 1。进一步开发了齐平的热膜风向是针对的技术 在脉动流中施用，墙剪应力逆转 方向。 提出的技术基于风速计的脉冲模式 桥梁操作。 2。通过实验确定弹性墙和非牛顿的影响 关于壁剪应力的空间和时间分布的流变学 脉冲流过弯曲的动脉模型。 我们将测量墙上的剪切 冲洗式热膜的压力在脉冲流中 通过甘油/水和弹性弯曲的动脉模型以及 分离/水溶液以及血液。 3。通过数值模拟弹性壁和 关于脉动流动的流体力学的非牛顿流变学 弯曲的动脉模型。 我们将首先延长僵硬的管，牛顿液 模拟以包括弹性墙。 最终我们将包括 非牛顿流变学。