Design, construction and evaluation of a system in electrical impedance tomography (EIT). Applications on cerebral tissue in rats

An electrical impedance tomography (EIT) system is presented for experimental applications in neurology fields such as epilepsy. The prototype consists of a semi-parallel system of 16 electrodes and a programmable current source. Rings of stainless steel electrodes with 4 mm radius were constructed. Experiments with adult wistar rats were performed for evaluation. Polar injection and backprojection methods were employed for obtaining images. Results showed a versatile prototype, its main characteristics being the current source, and methods of current injection and voltage measurements can be programmed via software. Results confirmed increased postmortem resistivity and other in vivo measurements.