Conductivities of pig dermis and subcutaneous fat measured with rectangular pulse electrical current

We examined experimentally the relationship between perpendicular and tangential electrical conductivities, sigma, and peak current density J, in pig skin dermis and subcutaneous fat specimens by using a four-electrode measuring system with rectangular pulse electrical current (RPEC). We also investigated the relationship of the conductivity, sigma, vs. pulse rate, f. The rates were selected at 8, 32, 64, and 128 pulses per second (pps), and the pulse width was fixed at 140 microseconds. These values are often used in vivo to enhance cutaneous regeneration with RPEC stimulation. It was found that the conductivities may be approximated to be [equation: see text] for the skin dermis and [equation: see text] for the subcutaneous fat in the conditions of this experiment. These findings implies that the conductivities of pig skin dermis and subcutaneous fat are anisotropic, i.e., sigma x = sigma y not equal to sigma z. It was also found that the conductivities are independent of current density and pulse rate in the current range from 20 microA/cm2 to 120 mA/cm2.