Fig. 7From: Lead field theory provides a powerful tool for designing microelectrode array impedance measurements for biological cell detection and observation a The simulated normalized transfer impedance magnitude spectrum and b locus for the four-electrode configuration. Without the cell (baseline) the magnitude spectrum (a) is a straight line. The impedance locus (b) exhibits the characteristic half ellipse. c The impedance at 100 kHz shown as a function of the horizontal position of the cell for different vertical distances from the MEA base plateBack to article page