Patent ID: 7974669

Claim:
A method for measuring a glucose concentration in blood, comprising the steps of: measuring an absorption spectrum that includes a wavenumber range of 1020-1040 cm −1 by pressing a forefinger to an ATR prism and receiving the reflected light by said forefinger; obtaining a second derivative spectrum by calculating the second derivative of said absorption spectrum for the wavenumber range 1020-1040 cm −1 ; determining, based on said second derivative spectrum, two peak points to be used as bases for an integration range, said two peak points being two upward peaks that surround a downward peak in the wavenumber range 1020-1040 cm −1 of said second derivative spectrum; obtaining an integrated value by integrating the absorption intensity in said absorption spectrum using said integration range that corresponds to said determined two peak points; and determining the glucose concentration in blood based on a relationship between pre-obtained integrated values and glucose concentrations, and said integrated value obtained from said absorption spectrum.