Lee Jung Yeop, Ji Ho Seong, Lee Sang Joon
Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea.
Physiol Meas. 2007 Oct;28(10):1149-62. doi: 10.1088/0967-3334/28/10/002. Epub 2007 Sep 18.
The hemodynamic characteristics of blood flow are important in the diagnosis of circulatory diseases, since such diseases are related to wall shear stress of cardiovascular vessels. In chicken embryos at early stages of development, it is possible to directly visualize blood flow inside blood vessels. We therefore employed a micro-PIV technique to assess blood flow in extraembryonic venous and arterial blood vessels of chicken embryos, using red blood cells (RBCs) as tracers and obtaining flow images of RBCs using a high-speed CMOS camera. The mean velocity field showed non-Newtonian flow characteristics. The blood flow in two venous vessels merged smoothly into the Y-shaped downstream vein without any flow separation or secondary flow. Vorticity was high in the inner regions, where the radius of curvature varied greatly. A periodic variation of temporally resolved velocity signals, due to beating of the heart, was observed in arterial blood vessels. The pulsating frequency was obtained by fast Fourier transform analysis using the measured velocity data. The measurement technique used here was useful in analyzing the hemodynamic characteristics of in vivo blood flow in chicken embryos.
血流的血流动力学特征在循环系统疾病的诊断中很重要，因为此类疾病与心血管壁的剪切应力有关。在鸡胚发育的早期阶段，可以直接观察到血管内的血流。因此，我们采用了显微粒子图像测速技术（micro-PIV）来评估鸡胚胚外静脉和动脉血管中的血流，使用红细胞（RBC）作为示踪剂，并使用高速互补金属氧化物半导体（CMOS）相机获取红细胞的流动图像。平均速度场显示出非牛顿流体流动特性。两条静脉血管中的血流顺利汇入下游的Y形静脉，没有任何流动分离或二次流动。在曲率半径变化很大的内部区域，涡度很高。在动脉血管中观察到由于心脏跳动导致的时间分辨速度信号的周期性变化。通过对测量的速度数据进行快速傅里叶变换分析获得脉动频率。这里使用的测量技术有助于分析鸡胚体内血流的血流动力学特征。
