Interaction of Elastic Vessel Wall and Arterial Blood Flow

弹性血管壁与动脉血流的相互作用

• 批准号: 02670618
• 负责人: SEKI Junji
• 金额: $ 1.41万
• 依托单位: National Cardiovascular Center Research Institute
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02670618/
• 关键词: Pulsatile flow; Elastic tube flow; Vessel wall elasticity; Laser-Doppler anemometer; Pulse propagation; Propagation velocity; Microvascular network; Spontaneously hypertensive rat; 乱流遷移; 脈波; レイノルズ数; ウォマ-スリ数

Effects of the elasticity of the vessel walls on the blood flow characteristics are studied in vitro and In vivo using laser-Doppler anemometers (LDA).In in vitro experiments, a flow apparatus was devised to produce a fully developed pulsatile flow of which Reynolds number and frequency parameter can be vaded for the ranges corresponding to those of the blood flow In the human large arteries. The flow tube was chosen to be 15 mm In diameter and 4.3 m long to produce the developed flow for the Reynolds number up to 5000. The pulsatile flow with non zero mean flow rate is generated by a rotating sheath and a slit put at the outlet of the flow tube. The flow velocity was measured by a 2-dimensional LDA system and the velocity profiles over the cross-section of the tube are obtained by traversing the LDA system. The velocity profile obtained under a steady flow condition was well represented by the Poiseuille velocity profile corresponding to the flow rate measured by an electromagnetic fl … More ow meter, which shows the flow was fully developed. The velocity profiles under a pulsatile flow condition showed a flow reversal near the tube wall in the phases of minimum flow although the total flow rate was always positiv during the pulsation period. Inflection points were also observed In the velocity profiles at the acceleration phases. These features of the pulsatile velocity profiles agree well with the theoretical expectations for the unsteady flow of an incompressible fluid through a straight circular cylinder. Elastic tube highly transparent for the measurement with LDA was made from polyurethane and the velocity measurement inside the elastic tube is in progress.In in vivo experiments, pulsation of the blood flow was studied in microvessels of the mesente ry of rats (SHR and WKY) by a fiber-optic laser-Doppler anemometer microscope (FLDAM) in relation to the rheology and the network topology of the microvessels. The phase lag of the microvascular flow relative to the carotid arterial pressure increased with decreasing diameter of arterioles in SHR mesentery, while there was little correlation between them In WKY. The propagation of the flow pulse In arterioles was theoretically treated by a porous tapered elastic tube model simulating the microvascular tree and the experimental results were analyzed based on this model. It was suggested from the model that the difference observed in the flow pulsation between SHR and WKY might be due to the longer arteriolar length and the fewer branch points in the SHR microvasculature than WKY. The velocity of the propagation of the flow pulse was also measured in arterioles with diameters from 10 to 30 mum to estimate the elastic property of single vessels. The propagation velocity was in the order of 10 cm/s and increased with the increasing vessel diameter, which is also consistent with the prediction derived from the porous tapered elastic tube model. Less

利用激光多普勒风速仪（LDA）研究了血管壁弹性对体外和体内血流特性的影响。在体外实验中，设计了一种流动装置，以产生完全发育的脉动流，其雷诺数和频率参数可以在与人体大动脉血流相对应的范围内变化。流管的直径为15mm，长为4.3 m，以产生雷诺数高达5000的发达流。通过在流管出口处设置旋转护套和狭缝，产生非零平均流量的脉动流。用二维LDA系统测量了管道的流速，并通过对LDA系统的遍历得到了管道横截面上的流速分布。在稳定流动条件下得到的速度分布与电磁流量计测得的流量所对应的泊泽维尔速度分布很好地反映了流动的充分发展。脉动流动条件下的速度分布在最小流量阶段在管壁附近出现流动反转，但脉动期间总流量始终为正。在加速阶段的速度分布中也观察到拐点。脉动速度分布的这些特征与不可压缩流体通过直圆柱的非定常流动的理论期望相吻合。用于LDA测量的高透明弹性管由聚氨酯制成，弹性管内的速度测量正在进行中。在体内实验中，利用光纤激光多普勒风速显微镜（FLDAM）研究了大鼠（SHR和WKY）间系微血管的血流脉动与微血管流变学和网络拓扑结构的关系。SHR肠系膜微血管流相对颈动脉压的相位滞后随着小动脉直径的减小而增大，而WKY中微血管流与颈动脉压的相关性不大。采用模拟微血管树的多孔锥形弹性管模型对微动脉内流动脉冲的传播进行了理论处理，并对实验结果进行了分析。从模型中可以看出，SHR和WKY之间的血流脉动差异可能是由于SHR的小动脉长度比WKY长，而SHR的微血管分支点较少。在直径为10 ~ 30微米的小动脉中测量了血流脉冲的传播速度，以估计单个血管的弹性特性。传播速度约为10 cm/s，且随着容器直径的增大而增大，这与多孔锥形弹性管模型的预测结果一致。少

项目成果

Seki,J.: "Pulsatile Change of Velocity Profiles in Microvessels Measured by a Fiber-Optic Leser-Doppler Anemometer Microscope" Microcirculation Annual-1991. 161-162 (1991)

Seki,J.：“通过光纤激光多普勒风速计显微镜测量的微血管速度分布的脉动变化”微循环年鉴 - 1991。

Junji Seki: "In Vivo Pulsatile Velocity Measurements in Microvessels by a FiberーOptic LaserーDoppler Anemometer Microscope" Abst racts of the First World Congress of Biomechanics. 2. 322 (1990)

Junji Seki：“通过光纤激光多普勒风速计显微镜进行体内微血管脉动速度测量”第一届世界生物力学大会摘要 2. 322 (1990)。

Seki, J. and Sugihara-Seki, M.: "High Temporal Resolution Measurement of Pulsatile Red Cell Velocity in Microvessels by a Fiber-Optic Laser-Doppler Anemometer Microscope" J. Jpn. Soc. Biorheology. 5. 80-87 (1991)

Seki, J. 和 Sugihara-Seki, M.：“通过光纤激光多普勒风速计显微镜对微血管中的脉动红细胞速度进行高时间分辨率测量”J. Jpn。

Seki,J.: "In Vivo Measurements of Velocity Profiles in Microvessels by a Fiber-Optic Laser-Doppler Anemometer Microscope" Med.Biol.Eng.Comp.29(Suppl). 736 (1991)

Seki,J.：“通过光纤激光多普勒风速计显微镜对微血管中的速度分布进行体内测量”Med.Biol.Eng.Comp.29（增刊）。

関 淳二: "光ファイバ型レ-ザドップラ流速計顕微鏡による微小血管内血流の高精度計測" 第6回流れの計測大阪シンポジウム講演要旨集. 1-5 (1991)

Junji Seki：“使用光纤激光多普勒电流计显微镜高精度测量微血管中的血流”第 6 届流量测量大阪研讨会摘要 1-5（1991 年）。