Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, Republic of Korea.
Microvasc Res. 2013 Nov;90:96-105. doi: 10.1016/j.mvr.2013.08.008. Epub 2013 Aug 30.
Platelet aggregation has been known to be closely influenced by the surrounding hemodynamic environments. Especially, platelet activation, aggregation, and thrombus formation frequently occur at the locally stenosed blood vessel where recirculation and stagnation flow regions are developed. However, the relationship between hemodynamic feature and platelet aggregation is not fully understood yet. The main objective of this study is to investigate the hemodynamic characteristics of blood flow in a stenosis channel and their effects on platelet aggregation. Whole blood was injected into a stenosed microchannel with 85% severity at various flow rates, ranging from 10 to 50mLhr(-1). The velocity vector field of the blood flow in the stenosed microchannel was measured using newly developed LED (light emitting diode)-illumination microparticle image velocimetry (micro-PIV). The blood flow is highly disturbed by the micro-stenosis, and a recirculation flow region is formed at the post-stenosis region. The occurring site and the shape of the platelet aggregation are highly influenced by the hemodynamic characteristics of blood flow around the stenosis. Especially, the platelet aggregation is found to occur at the interface where the downward momentum of the central jet at the post-stenosis region and the upward momentum of the recirculation flow are balanced. These experimental results would be helpful to understand the platelet aggregation under disturbed blood flow conditions.
血小板聚集已被证明受到周围血液动力学环境的密切影响。特别是在局部狭窄血管中，血小板的激活、聚集和血栓形成经常发生，此时会出现再循环和停滞流区域。然而，血流动力学特征与血小板聚集之间的关系尚未完全清楚。本研究的主要目的是研究狭窄通道中血流的血液动力学特征及其对血小板聚集的影响。全血以 10 至 50mLhr(-1) 的不同流速注入狭窄度为 85%的狭窄微通道。使用新开发的 LED（发光二极管）照明微粒子图像测速法（micro-PIV）测量狭窄微通道中血流的速度矢量场。微狭窄严重干扰了血流，在狭窄后区域形成了一个再循环流区域。血小板聚集的发生位置和形状受到狭窄周围血流动力学特征的强烈影响。特别是，血小板聚集发生在狭窄后区域中心射流的向下动量和再循环流的向上动量平衡的界面处。这些实验结果有助于理解在受干扰的血流条件下的血小板聚集。
