Electrical impedance tomography for local biological tissue

Electrical impedance tomography (EIT) is 2D or 3D image of electrical impedance distribution in a living tissue. It has become expected as a different method to obtain a tissue characteristic for various medical diagnoses. To realize a practical EIT measurement system, it is an important subject to choose a proper configuration of the electrodes, because the EIT is estimated from impedance data, which is measured non-invasively by surface electrodes. In this study, a new configuration of the electrodes, called divided electrode, is proposed for a short time measurement of bio-impedance in a cross section of a local tissue. Its capability is examined by computer simulations, where a distributed equivalent circuit is used as a model in the cross section of the tissue. Estimation of impedance parameters is carried out by use of the Newton method. Usefulness of the proposed method is confirmed by computer simulations using a typical layered tissue model.