SKIN HYDRATION STATE ESTIMATION USING A FIBEROPTIC REFRACTOMETER

A U-shaped fiber-optic refractometer is used to estimate the hydration state of human skin. The validity of the sensor in this application h as been investigated by comparing the sensor output with the conductan ce of the skin to a high-frequency electrical current of 3.5 MHz, whic h has been reported to be a good measure of the skin hydration state. Results indicate that there is a relatively close relationship between the optical sensor output and the electrical conductance. A water sor ption-desorption test conducted to confirm the above relationship has revealed that the fiber-optic probe can provide a convenient means for estimating the skin hydration state in an easy manner.