Design and simulation of a current source for electrical impedance tomography

In the last years, they've developed a large number of techniques to take images of the biological tissues. One of these new systems is Electrical Impedance Tomography. In this system (EIT), currents or voltages are applied to the surface of a volume, an electromagnetic field is established inside the volume and resulting voltages or currents that appear on the surface of the volume are measured. This system involves of: Current source, multiplexer board, Injecting and recording electrodes of electrical signal, A-D board, central computer for processing and showing electrical signals as images. The main part of this system is current source which must have high output impedance, high signal to noise ratio and wide band frequency. In this paper, the design, simulation and prototyping of a controlled current source for EIT are explained, and experimental results demonstrate the theoretical operation of this current source.