Boundary element method and internal electrodes in electrical impedance tomography

Traditionally in electrical impedance tomography an approximation for the i nternal resistivity distribution is computed based on the knowledge of the injected currents and measured voltages on the surface of the object. Howev er, in certain applications it is also possible to use internal current sou rces and voltage measurements. In this paper we propose a boundary element- based method which utilizes data also from internal electrodes in the image reconstruction. The proposed approach assumes that the internal geometry i s known a priori and only the conductivities of the predetermined regions a re estimated. Two-dimensional simulations with four additional sources/meas urement locations show clear improvement in the reconstructed images when t he results are compared to those based only on boundary data. Copyright (C) 2001 John Wiley & Sons, Ltd.