Patent ID: 7974670

Claim:
A measuring method comprising the steps of: irradiating a white light to a biological surface as a sample; detecting a spectrum of the white light reflected from two or more positions on said biological surface; plotting an absorbance of said spectrum to a spectral multi-dimensional space of light; conducting a multivariate analysis of a data on said spectral multi-dimensional space obtained from said two or more positions to obtain eigenvectors of at least first, second and third principal components; and projecting the data of each position onto a direction of the eigenvector of said at least three principal components to measure at least one of a total amount of hemoglobin, an amount of melanin, an amount of talaporfin, and a difference in amount between oxygenated hemoglobin and reduced hemoglobin, which exist on said biological surface, based on a magnitude of the component of said data with respect to the direction of said eigenvector.