Patent ID: 7653424

Claim:
An apparatus for measuring blood glucose levels, comprising: (a) an irradiating means for irradiating light onto the eye of a user from outside the cornea of the eye to excite an ocular glucose sensor, wherein said ocular glucose sensor is in contact with an ocular fluid and can emit a total fluorescence having a first and a second wavelength bands upon irradiation with said irradiating means; (b) an optical path splitting means for splitting said total fluorescence having both bands into a first fluorescence having said first wavelength band and second fluorescence having said second wavelength band, wherein said first fluorescence travels along a first optical path and said second fluorescence travels along a second optical path; (c) a first detecting means located in the first optical path for detecting the intensity of the first fluorescence at a first wavelength; (d) a second detecting means located in the second optical path for detecting the intensity of the second fluorescence at a second wavelength; (e) a calculating means for calculating the intensity ratio of the first fluorescence to the second fluorescence and for determining based on the calculated intensity ratio an ocular glucose concentration in the ocular fluid of the user according to a predetermined calibration table or calibration curve; and (f) an arithmetic means for converting the ocular glucose concentration determined by the calculating means into a blood glucose concentration by referring to a predetermined correlation between blood glucose concentrations and ocular glucose concentrations.