Long-wavelength near-infrared spectroscopic imaging for in-vivo skin hydration measurements

A digital imaging system has been developed to collect skin hydration data. The system combines a near-infrared camera with a liquid-crystal tunable filter (LCTF) to acquire spectral images at multiple narrow wavelength bands between 960 and 1700 nm. Software has been developed to control the instrument and to process the data. Reflectance images were collected of subjects whose forearms had been treated to increase and decrease skin moisture. The infrared absorption band between 1400 and 1500 nm was used to calculate relative skin moisture, and the intensity of this band was plotted as a function of position in the form of a grayscale image. This is a rapid, non-contact and non-invasive technique to provide information on skin hydration of use to medical and cosmetic research and clinical practice. (C) 2002 Elsevier Science B.V. All rights reserved.