Using micro electrode array for on-line EIT measurement

Abstract

The traditional Electrical Impedance Tomography (EIT) is done in a way by providing a plurality of mutually spaced electrical contacts mounted at the outside wall of the ring and electrically contacting with the ring, applying currents or voltages to generate a more homogeneous electric field distribution within the material, measuring voltage or current distribution alone the ring from other electrical contacts. However, the accuracy of the reconstruction in the central area of the tank is relatively poor compared to the peripheral area near the electrode ring. In order to achieve better reconstruction for the central area, we propose a new EIT method in this paper by using other electrode configurations available e.g. by using the Micro Electrode Arrays (MEA). We simulated the EIT process by using an 8x8 electrode array below an inhomogeneous media with 20dB added Gaussian noise. The adjacent current pattern is applied to the electrodes in a way similar to the traditional EIT, and then, the measured voltages are used for reconstruction. Four different algorithms are utilized and compared during the reconstruction process. For evaluation of the accuracy of our method, we use the Correct Reconstruction Rate (CRR) and False Acceptance Rate (FAR) as the quantitative criterions. Our method produce a performance with CRR=100% and FAR=0.54% over a mesh with 784 elements using Laplace reconstruction. Furthermore, the small scale and fast calculation are the additional advantages of our method. Future research will be directed to the simulation of 3D case. © Springer-Verlag 2007.