Dynamic electrical impedance tomography -: Phantom studies

In electrical impedance tomography (EIT) an approximation for the internal resistivity distribution is computed based on the knowledge of the injected currents and measured voltages on the surface of the body. In some applications the resistivity changes may be so fast that the information on the time evolution of the resistivity distribution is either lost or severely blurred. In this paper we study with phantom experiments the capabilities of the earlier proposed approaches, Kalman filter and Kalman smoother. We show that in "two-dimensional" phantom these approaches are capable of reconstructing a sequence of absolute images of a moving object, By an absolute image we mean that no additional reference voltage measurement is needed for the image reconstruction. An image is obtained after each current injection. Also, when compared to traditional reconstructions, the dynamic approaches reveal much more information about the dynamic behaviour of the object.