Examination of amount of moisture of adult female's forearm epidermal stratum corneum with two kinds of impedance sensors

Abstract

Amount of skin moisture of adult female's forearm epidermal was measured with two kinds of impedance sensors with different metrology, and the effectiveness to continuance observation for general health care was confirmed. Admittance skin moisture meter based on electrical skin admittance, was employed two-electrode method, a sinusoidal wave voltage (100kHz, 2V) was applied to the electrode. The measurement depth, that is, evaluated area is surface of stratum corneum. Another one, moisture checker was based on electrostatic capacity method, because there are positive correlations in the amount of moisture and the permittivity. The measurement depth is in the entire of the stratum corneum. The subjects were 255 women in 25-74 years old. Measurement period was 16 months from March to June next year. Results and conclusions were as follows: 1.The mean value of the skin moisture was 86.1μS with admittance skin moisture meter, and 37.6% with moisture checker. There was excellent relation between the values measured with two methods. 2. The change in the skin moisture appeared greatly in the admittance skin moisture meter, and it appeared minute difference in the moisture checker. The change appears greatly so that admittance skin moisture meter may chiefly detect the skin surface part, the change became small with moisture checker may detect the whole of the stratum corneum. 4. The skin moisture was seasonal dependent; in summer or August results in maximum.