Blood cell counting by means of impedance measurements in a microsystem device

This paper presents an innovative, portable and low power blood cell counter, based on micro-electro-mechanical-systems (MEMS) technology. It was realized by designing and developing a custom impedance measurement circuit, which drives an electro-fluidic microsystem, providing a parallel, multi-channel Coulter counter. A method for a reliable, easy, and low-cost interfacing to such kind of micro-devices, allowing both fluidic and electric coupling, is also shown. Preliminary experiments led to promising results: fluidics works properly without leakages or clogging. Electrodes show good stability with current (in terms of adhesion), and measured channel impedances are satisfyingly low (30 kW for a cubic Coulter orifice, side 10 microm). Finally, we present a possible extension of the setup, based on a dual-characteristic, electro-optical counting.