Influence of water and temperature on the electrical conductivity of the human nail

Abstract

The human toenail was measured in vitro in the alpha-dispersion region of the electric field and the temperature from 22 to 150°C. The values of dielectric properties are much higher in the wet nails than in those without water of the same temperature and frequency. The peak temperature of dielectric parameters near 100°C for wet nails is attributed to the water removal process. The dielectric spectra of the nail revealed high-frequency relaxation at 25 kHz irrespective of the water content in the tissue. Our dielectric studies of the nail plate enable deeper analysis of the matrix-keratin-water system, which can facilitate the assessment of the electrical conductivity of this tissue in the state of health and diseased.

Computational Modelling for Electrical Impedance Spectroscopy-Based Diagnosis of Oral Potential Malignant Disorders (OPMD)

“…Electrical characterisation of keratin with varying hydration shows a large decline in resistivity [ 25 ], which was reflected in our model by the systematic reduction in assigned resistivity values. When keratinised layer resistivity was reduced to 1 kΩm, expected trends with underlying tissue dysplasia (i.e., lower impedance for OPMD spectra) were recovered ( Figure 7 ).…”

“…Initially, the keratinised layer was assigned the electrical properties of pure keratin [ 24 ]. Literature values show the resistivity reduces with increasing hydration [ 25 ]; in the context of oral tissue, this is likely due to a higher concentration of mobile ions, plus potentially wider extracellular routes available for conduction (the latter being important at low frequencies). To test the effect of hydrated keratin properties, keratinised normal and OPMD tissue, simulations using layer thicknesses from Table 1 (cases 2 and 4 respectively) were performed.…”