The electrical activity plays a vital role in the physiological functions of live organisms, electrical stimulation has been identified as a promising nonpharmacological technique that can modulate the behavior of cellular network, restore and monitoring critical functions and accelerate tissue healing in vitro and in vivo. The red blood cell (RBC) membrane contains proteins and glycoproteins embedded in a fluid lipid bilayer that confers viscoelastic behavior. Sialylated glycoproteins of the RBC membrane are responsible for a negatively charged surface which creates a repulsive electric zeta potential (ζ)between cells. These charges help prevent the interaction between RBCs and the other cells and especially between each other. The zeta potential is a physical property which is exhibited by all particles in suspension. In this context we present for the first time the invention concerns the field of measurement of physiological parameters for determining cardiac output (CO), plus specifically refers to a new apparatus for determination of cardiac output based on determination of the electrical charges induced on the membrane of the RBC (electrical polarization of red blood cells).