Fig. 1From: Optimal combination of electrodes and conductive gels for brain electrical impedance tomographya Measurement results of three known resistors (251.12 Ω, 1.99 kΩ and 14.98 kΩ). b Measured impedance spectra from 10 volunteers for the combination eA-gA. c Mean contact impedances of all combinations of electrode and conductive gel within 100 Hz-1 MHz. eX-gY represents the combination of electrode X and conductive gel YBack to article page