A step-by-step development of an electrical impedance tomography system

Summary form only given. Electrical impedance tomography (EIT) is a new imaging modality aiming at the reconstruction of an object\´s conductivity or permittivity distribution. There are a lot of possible applications but the most promising are those in medicine and geophysical prospecting (including archeology). This paper is restricted to the medical applications, since they are of particular interest. EIT medical imaging is established on the fact that biological tissues can be recognized from their conductivity (σ) or permittivity (ε), which in turn vary according to its state of health as well as during physiological organs functioning. An EIT imaging system consists of its data collection-measurement sub-system and its reconstruction algorithm. The purpose of this paper is to clearly identify a step-by-step development procedure of an EIT system. First the basic EIT principles are reviewed along with the basic assumptions involved. The development procedure is defined in three major steps: (i) the "computer", (ii) the "laboratory or in-vitro" and (iii) the "clinical or in-vivo" tests. This work deals with the first two test, namely the computer and the laboratory ones. Both the measurements-data collection and reconstruction,. algorithm development procedures are explained. The development of a resistive network and a tank laboratory phantom, as well as the comparison of the measured and calculated results is then considered. Finally, reconstructed images from laboratory phantoms are presented and compared against the target model