title: Estimation of melanin and hemoglobin using spectral reflectance images reconstructed from a digital RGB image by the Wiener estimation method.
abstract: A multi-spectral diffuse reflectance imaging method based on a single snap shot of Red-Green-Blue images acquired with the exposure time of 65 ms (15 fps) was investigated for estimating melanin concentration, blood concentration, and oxygen saturation in human skin tissue. The technique utilizes the Wiener estimation method to deduce spectral reflectance images instantaneously from an RGB image. Using the resultant absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are numerically deduced in advance by the Monte Carlo simulations for light transport in skin. Oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments on fingers during upper limb occlusion demonstrated the ability of the method to evaluate physiological reactions of human skin.
authors.affiliation: Graduate School of Bio-applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, 184-8588 Tokyo, Japan. inishi@cc.tuat.ac.jp
authors.forename: Izumi
authors.initials: I
authors.lastname: Nishidate
authors.forename: Takaaki
authors.initials: T
authors.lastname: Maeda
authors.forename: Kyuichi
authors.initials: K
authors.lastname: Niizeki
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Aizu
mesh_terms: D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008543:Melanins / Q000032:analysis* / Q000097:blood; D009010:Monte Carlo Method; D010100:Oxygen / Q000378:metabolism; D012044:Regression Analysis; D012867:Skin / Q000378:metabolism; D013053:Spectrophotometry
chemical_list: D006454:Hemoglobins; D008543:Melanins; D010100:Oxygen