INVESTIGATION, BY ELECTROHYDRODYNAMIC ADMITTANCE MEASUREMENTS, OF THE INFLUENCE OF CELL MORPHOLOGY, WALL POTENTIAL, AND HEMATOCRIT ON THE FLOW OF SUSPENSIONS OF RED-BLOOD-CELLS IN THE VICINITY OF THE WALL

The flow generated by a disc electrode rotating in a suspension of hardened discoidal or spherical red blood cells is investigated by measuring the electrohydrodynamic admittance of the system. This recent electrochemical method consists in studying the current response, relative to the electrochemical oxidation of the ferrocyanide anion acting as a mass transport tracer in the suspension, to a sinusoidal perturbation of the disc rotation speed. Cell morphology, electrode potential and hematocrit are shown to influence electrohydrodynamic admittance. The last two parameters are mutually dependent due to a variation of the local hematocrit with the potential in the vicinity of the electrode. The variations of the admittance generated by each of these parameters are tentatively related to variations of the velocity field in the vicinity of the electrode. The physiological morphology of the red blood cell leads to a very particular flow characterised by a non-dependence of the fluid axial velocity on the time-derivatives of the perturbation. © 1979.