Preliminary study of a Cole-Cole model curve fitting method for Electrical Impedance Tomography

Abstract

The majority of tissue characterizations through electrical impedance tomography are based on the Cole-Cole model. The frequency dependant model can be used to describe both the intra- and extra-cellular characteristics of a tissue under investigation between zero and infinite frequencies. However, such measurements can be difficult to achieve at very high frequencies with the required signal to noise ratio (SNR). Therefore, fitting techniques are of critical importance to provide the required quality of data for EIT analysis, in particular for parametrical images. This paper will present an analysis of two fitting techniques that can be used to determine Cole-Cole parameters (R, S, C, characteristic frequency and dispersion characteristic). The methodologies are performed on a number of curves with analyses being made of the introduced errors and the potential for calibration of the fitting technique based upon said analyses. © Springer-Verlag 2007.