Abstract
This paper explains the construction of equivalent circuit with fixed elements for skin impedance which satisfy the Cole-Cole circular arc law.
The Cole-Cole dispersion system having continuously distributed relaxation times can be simulated by the system of some discrete relaxation times, and approximate equation is assumed as follows :
P (ω) =Z (ω) -Z∞/Z0-Z∞=1/1+ (jωτm) β≅n∑i=1Ri/jωCiRi/n∑i=1Ri
where Z (ω) is skin impedance and the suffixes 0 and co refer to zero and infinite angular frequency.βandτmare parameters of the Cole-Cole arc. To determine the optimum coefficients Ri Ci of thisequation some conditions and evaluation function are provided. Ri, Ci< are frequency-independent fixed elements. Then, optimum coefficients were obtained for β=0.5-0.9 for the cases n=3, 5, 7. The equivalent circuit, constructed by n series arrangements of parallel resistance Ri and capacitance Ci combination and series resistance Z∞, simulates in good agreement skin impedance over the wide frequency range. It is useful to the simulator of skin impedance in the case, for example, of signal distortion caused by skin impedance appearing : in, electrocardiography.
