Fractional-Order Bio-Impedance Modeling for Interdisciplinary Applications: A Review

Bio-impedance circuit modeling is a popular and effective non-invasive technique used in medicine and biology to fit the measured spectral impedance data of living or non-living tissues. The variations in impedance magnitude and/or phase at different frequencies reflect implicit biophysical and biochemical changes. Bio-impedance is also used for sensing environmental changes and its use in the agriculture industry is rapidly increasing. In this paper, we review and compare among the fractional-order circuit models that best fit bio-impedance data and the different methods for identifying the parameters of these circuits. Four different vegetables species (Carrot, Tomato, Zucchini, Cucumber) in three different conditions (fresh, frozen, and heated) are used to demonstrate the differences among these models.