A simple method to check the dynamic performance of electrical impedance tomography systems

The test concept as well as the design of a simple resistor phantom suitabl e for the evaluation of the properties of electrical impedance tomographic (EIT) systems is presented. Input and transfer impedance of the phantom are marched with those of the human thorax. Amplitude of the local impedance v ariations similar to in vivo conditions (ventilation) can be intentionally set to perform measurements on different states. The theoretical potential differences between the electrodes are calculated. The evaluation procedure is performed in terms of the local amplitude of the relative impedance cha nge as well as the local distribution of noise. The whole procedure can be applied either to compare quantitatively the performance of different EIT d ata acquisition systems or to determine the amount of measurement disturban ce caused by the external electrical environment in clinical settings.