Patent ID: 7215982

Claim:
A method for measuring the concentration of a specific component contained in a living body comprising the steps of: (1) introducing light into an optical element, which is absorbed and reflected by a living body in contact with said optical element and then emitted from said optical element: (2) detecting the light emitted from said optical element and obtaining a wavenumber signal from the detected light: (3) correcting said wavenumber signal with the use of a calibration line for correcting the influence of a change in the state of an interface between said living body and said optical element on said wavenumber signal, (4) obtaining the concentration of the specific component contained in said living body from the corrected wavenumber signal; and (5) outputting the concentration of the specific component, wherein said calibration line is prepared by the steps of: (3a) obtaining “i” different spectrums corresponding to “i” different states of said interface, where said “i” is an integer from 2 to n; and (3b) plotting “i” different points in a coordinate system and connecting said points to obtain a calibration line, each of said “i” different points being determined from “j” different wavenumber signals corresponding to “j” different wavenumbers in each of said “i” different spectrums, where said “j” is an integer from 2 to n.