Velocity profiles of blood flow in microvessels measured by ten channels' dual-sensor method

Ten channels' dual-sensor method newly developed was applied to the measurement of velocity profiles in arterioles and venules in the rat mesentery. In some experiments, red blood cells (RBC), labelled in vitro with a fluorescein isothiocyanate (FITC), were injected to compare the velocity profiles obtained by the RBC visualization technique with those measured by the dual-sensor method. It was found that the velocity profile of the FITC labelled RBC in straight microvessels was blunt as compared to a parabola. The centerline velocity measured by the dual-sensor method was smaller than that of the FITC labelled RBC by about 20%. The velocity profiles were also measured at the curved arterioles and venules as well as at the bifurcation and the confluence. It was found that the velocities were higher along the inner wall at the curved portion and along the outer wall at the bifurcation of arterioles.