人体颈内静脉内血流流动类型和非稳态特征研究

Recent researches indicated that some cerebral diseases, such as multiple sclerosis and panic disorder, had significant correlations with blood flow in internal jugular veins. Gravity induced negative pressure was usually regarded as main reason for collapse of human internal jugular vein during posture changing. However, blood pressure in cerebral vein system would be much lower if blood pressure in internal jugular vein was negative. Meanwhile, blood flow in internal jugular vein would be subcritical flow. But experimental results showed that blood flow in internal jugular vein of giraffe, which was much longer than that of human, was supercritical and time-dependent. These facts indicated that there might be some misunderstandings on collapse behavior of human internal jugular vein. In this project, we would investigate the flow types and time dependent characters of blood flow in human interal jugular veins through carrying out tilt tests and doing computational fluid dynamics analysis. True reasons that caused collapse of human internal jugular were expected to be cleared through this research, which would benifit our understanding on mechanism of those cerebral diseases mentioned above.

研究表明多发性硬化和恐慌症等脑病与颈内静脉内血流动力学状态显著相关，但具体血流动力学机理尚不清楚。颈内静脉易发生塌陷，导致其血流动力学特性表现出高非线性，由重力引起的血管内负压通常被认为是导致塌陷的主要原因。但这种理解在用于解释脑静脉系统血压水平时存在问题，且与动物实验结果存在矛盾。本课题旨在通过研究颈内静脉内的血流流动类型和非稳态特征，揭示颈内静脉塌陷的生物力学机理。申请者拟利用彩色多普勒超声技术获得倾斜实验中健康成年人体在不同姿势下的颈内静脉图像和血流速度，结合图像处理算法和计算流体力学理论重构颈内静脉的三维几何结构和内部三维流场分布，在此基础上研究颈内静脉内的血流流动类型和非稳态特征，获得颈内静脉血流动力学特性的定量化描述。此研究可为实现脑血循环的定量化研究提供新的理论依据和数据支持，有助于推动相关脑病发生机理的血流动力学研究。

研究表明多发性硬化和恐慌症等脑病与颈内静脉内血流动力学状态显著相关，但具体血流动力学机理尚不清楚。颈内静脉易发生塌陷，导致其血流动力学特性表现出高非线性，由重力引起的血管内负压通常被认为是导致塌陷的主要原因。但这种理解在用于解释脑静脉系统血压水平时存在问题，且与动物实验结果存在矛盾。本课题完成了以下研究内容：（1）利用彩色多普勒超声技术获得倾斜实验中20名健康成年人体在不同姿势下的颈内静脉图像，对颈内静脉塌陷过程的几何形态进行了分析，以此为基础实现了三维模型重构与内部流场的重建；（2）依据重建的三维几何模型和内部流场，获取了用于颈内静脉集中参数建模的血管顺应性、流体粘性阻力和流体惯性在不同塌陷程度下的定量变化规律；（3） 构建了能够模拟颈内静脉塌陷和脑血回流通道姿势依赖性的集中参数模型，并完成了模型的验证工作，验证结果表明本研究所建基于颈内静脉塌陷特征的脑血回流通道模型能够准确模拟脑血回流通道的姿势依赖性，可为实现脑血循环的定量化研究提供新的理论依据和数据支持，有助于推动相关脑病发生机理的血流动力学研究。