Modeling of Human Skin using Distributed Order Fractional Derivative Model-Frequency Domain

Abstract

Bioelectro-mechanical properties of the skin can be very valid data for analyzing fractal characteristics of skin structure. In this paper, bioelectrical impedance method and fractional calculus have been utilized for characterization of the human skin. Our fractional model presents the generalized continuous Cole model which can predict structural – functional parameters as a lot of Cole complex relaxation times. It is shown using the proposed model and experimental results that these parameters depend on the fractional indexes as a degree of the fractional derivatives in the interval (0,1). These relaxation time constants correspond to structural – functional characteristics of the skin. The integral approximation of continuous fractional Cole model was done from ten points corresponding to orderly connected known reduced Cole elements. It was observed that five reduced Cole elements had significant values of corresponding relaxation times. Lastly, the advantages of the proposed model are discussed.