Simultaneous measurement of velocity field and RBC aggregation of pulsatile blood flow using ultrasound speckle image velocimetry

Variations of hemodynamic parameters have been known as an important factor for various cardiovascular diseases. Accurate measurement of wall shear stress in blood vessels is essential for early detection and therapeutic treatments of cardiovascular diseases [1]. For that, many velocity field measurement techniques have been proposed and developed. However, the accurate in vivo measurement of the wall shear stress remains a problematic task due to the shear-thinning feature of blood flows. Red blood cells (RBCs) aggregation is a phenomenon that RBCs aggregate and form rouleaux and rouleaux networks. RBC aggregation is totally responsible for the non-Newtonian flow feature. In addition, RBC aggregation is closely related to microcirculatory disorders such as atherosclerosis, diabetes and other cardiovascular diseases [2, 3]. An ultrasound speckle image velocimetry (SIV) was employed for simultaneous measurement of velocity fields and RBC aggregation under pulsatile blood flows