An Integrated Circuit for Tissue Impedance Measure

In this paper, the design of aa Integrated Circuit (IC) for the measurement of tissue impedance is presented. The chip is intended to be used in monitoring biomedical parameters in living bodies. Tissue impedance is one of these parameters which allows ischemia monitoring. The designed IC is used in a four-electrode based set-up in order to minimize the effect of electrode-electrolyte interface impedance. A needle shaped probe which contains the four electrodes for the impedance measurement and Integrated Circuits (ICs) required for excitation and measurement purpose have been designed, fabricated and tested in-vivo. The IC has been fabricated in a 0.8μm CMOS process, working at 3V of power supply. Test results have shown the circuit feasibility.