Dynamic inverse obstacle problems with electrical impedance tomography

Electrical impedance tomography (EIT) is a relatively new imaging modality in which the internal resistivity distribution is reconstructed based on the known sets of injected currents and measured voltages on the surface of the object. In this paper, a dynamic inverse obstacle problem is considered based on the electrical impedance tomography. The considered situation here is for the case where the shape and location of the obstacle are known a priori whereas the resistivity of the obstacle changes rapidly in time. The inverse problem is treated as nonlinear state estimation problem and the unknown time-varying state (resistivity) is estimated on-line with the aid of the extended Kalman filter. The reconstruction performance is enhanced considerably by taking into account the first- or second-order time-derivative of the resistivity change in the obstacle. (C) 2004 IMACS. Published by Elsevier B.V. All rights reserved.