A PXI based system for electrical impedance tomography

In this paper, a PXI based system for electrical impedance tomography (EIT) will be presented. A virtual instrument based on the PXI platform is used to inject current and to acquire voltage data on a 16 electrode perspex phantom filled with saline or gelled solutions that mimic human body tissues. The admittance method is used for the solution of the direct problem and a modified Newton-Raphson algorithm is used for the image reconstruction. Experimental measurements have been performed on saline or gelled solutions to establish a link between the salt concentration and the solution conductivity. A set of measurements has been performed on phantoms simulating, at various levels of approximation, the human body anatomy. The results indicate that the proposed EIT system is efficient and accurate. Moreover its modular structure makes it possible to test various data collection protocols and inversion algorithms.