Lateral migration of blood cells and microspheres in two-dimensional Poiseuille flow: a laser-Doppler study.

The inertia-induced lateral migration of rigid microspheres, platelets and erythrocytes is studied experimentally. The concentration and velocity profiles of the particles have been determined with a laser-Doppler anemometer designed for high resolution measurements. Data are compared with empirical and analytical models on inertia-induced lateral migration of rigid spheres. Experiments done in rectangular flow channels of high aspect ratio reveal that at a sufficiently high particle Reynolds number, platelets exhibit tubular pinch effects comparable with those of rigid polystyrene microspheres. Erythrocytes also exhibit inertia-induced lateral migration at high particle Reynolds number and low medium viscosity. At a higher medium viscosity, erythrocytes show deformation-induced lateral migration towards the center of the flow channel.