The moisture content measurement of human skin is a significant way to assess skin conditions and diagnose diseases that influence skin function.The necessity of evaluating the efficacy of a cosmetic product makes it ...The moisture content measurement of human skin is a significant way to assess skin conditions and diagnose diseases that influence skin function.The necessity of evaluating the efficacy of a cosmetic product makes it important to improve the accuracy and reproducibility of the measurement.A pair of interdigitated gold electrodes was fabricated on the printed circuit board (PCB) substrate and utilized directly in contact with the measured skin.A square-wave voltage at a single frequency was applied to the electrodes and the corresponding response current was measured to get the equivalent impedance of human skin.Since it's easy to generate and control a square-wave signal by digital electric circuits,this method is suitable to be used in the portable application.The experimental results indicate that good repeatability and satisfied accuracy can be obtained by this method.展开更多
Pathology of an internal organ causes significant rectification of electrical currents (diode phenomenon) in related skin areas - organ projection areas (OPAs), once the resistance ‘breakthrough effect' has been...Pathology of an internal organ causes significant rectification of electrical currents (diode phenomenon) in related skin areas - organ projection areas (OPAs), once the resistance ‘breakthrough effect' has been induced in the skin. Also, the impedance of the diseased organ's projection areas is increased. The aim of this double-blind study was to confirm these phenomena statistically using a broad spectrum of measuring parameters. Skin impedance vs. measurement frequency, skin impedance vs. applied voltage, and skin resistance vs. voltage were evaluated at 335 auricular OPAs related to the healthy internal organs and 203 auricular OPAs related to the diseased organs. These measurements confirmed that the skin electrical characteristics of specific locations are dependent on the health state of the corresponding internal organs. It was found that the impedance of OPAs corresponding to the healthy internal organs equals 185 + 291 k,Q at 10Hz and decreases to 64 ± 49 kΩ at 10kHz; and that the impedance of OPAs related to the diseased organs equals 7.5 ± 2.2 MΩ at 10Hz and 99 ± 50kΩ at 10kHz. The disparity of the impedances between the healthy and diseased organs related OPAs is greater at higher potentials. The skin resistance, when measured with a negatively polarized point electrode, undergoes a rapid resistance decrease of approximately two orders of magnitude, if the applied current is sufficient. After this reversible ‘breakthrough effect' is obtained the skin exhibits rectification. The degree of rectification is low for OPAs related to the healthy organs. For OPAs related to the diseased organs, the resistance measured with a positive polarisation of measuring electrode could be five times greater than the resistance measured at the same voltage with the same but negatively polarised electrode. The disparity between the resistance measured with a negatively and with a positively polarised electrode at OPAs related to the diseased organs was greater at higher measurement voltages. The influence of organ pathology on the electrical parameters of related OPAs does not depend on the kind of internal organ and is not affected by the etiology of pathology. The degree of rectification or difference in impedance is proportional to the extent of the pathological process within the related organ.展开更多
文摘The moisture content measurement of human skin is a significant way to assess skin conditions and diagnose diseases that influence skin function.The necessity of evaluating the efficacy of a cosmetic product makes it important to improve the accuracy and reproducibility of the measurement.A pair of interdigitated gold electrodes was fabricated on the printed circuit board (PCB) substrate and utilized directly in contact with the measured skin.A square-wave voltage at a single frequency was applied to the electrodes and the corresponding response current was measured to get the equivalent impedance of human skin.Since it's easy to generate and control a square-wave signal by digital electric circuits,this method is suitable to be used in the portable application.The experimental results indicate that good repeatability and satisfied accuracy can be obtained by this method.
文摘Pathology of an internal organ causes significant rectification of electrical currents (diode phenomenon) in related skin areas - organ projection areas (OPAs), once the resistance ‘breakthrough effect' has been induced in the skin. Also, the impedance of the diseased organ's projection areas is increased. The aim of this double-blind study was to confirm these phenomena statistically using a broad spectrum of measuring parameters. Skin impedance vs. measurement frequency, skin impedance vs. applied voltage, and skin resistance vs. voltage were evaluated at 335 auricular OPAs related to the healthy internal organs and 203 auricular OPAs related to the diseased organs. These measurements confirmed that the skin electrical characteristics of specific locations are dependent on the health state of the corresponding internal organs. It was found that the impedance of OPAs corresponding to the healthy internal organs equals 185 + 291 k,Q at 10Hz and decreases to 64 ± 49 kΩ at 10kHz; and that the impedance of OPAs related to the diseased organs equals 7.5 ± 2.2 MΩ at 10Hz and 99 ± 50kΩ at 10kHz. The disparity of the impedances between the healthy and diseased organs related OPAs is greater at higher potentials. The skin resistance, when measured with a negatively polarized point electrode, undergoes a rapid resistance decrease of approximately two orders of magnitude, if the applied current is sufficient. After this reversible ‘breakthrough effect' is obtained the skin exhibits rectification. The degree of rectification is low for OPAs related to the healthy organs. For OPAs related to the diseased organs, the resistance measured with a positive polarisation of measuring electrode could be five times greater than the resistance measured at the same voltage with the same but negatively polarised electrode. The disparity between the resistance measured with a negatively and with a positively polarised electrode at OPAs related to the diseased organs was greater at higher measurement voltages. The influence of organ pathology on the electrical parameters of related OPAs does not depend on the kind of internal organ and is not affected by the etiology of pathology. The degree of rectification or difference in impedance is proportional to the extent of the pathological process within the related organ.