Patent ID: 6704110
Filing Date: 2004-03-09
Classification: A61B,G01N

Abstract:
A measuring method of internal information of a scattering medium, comprising:a light injecting step of injecting pulsed light of two or more predetermined wavelengths into a scattering medium at a light injection position; a light detecting step of detecting the light of said two or more predetermined wavelengths having propagated inside said scattering medium, at a photodetection position to acquire a photodetection signal; a signal processing step of acquiring waveform data indicating a temporal change of intensity of the detected light, based on said photodetection signal; a mean pathlength and variance computing step of performing an operation to compute a mean pathlength of plural photons composing said detected light, and a variance, based on said waveform data; and an absorption coefficient difference calculating step of calculating a difference between absorption coefficients at said predetermined wavelengths, based on a predetermined relation holding among said mean pathlength, said variance, and the difference between the absorption coefficients at said two or more predetermined wavelengths.