초록 ▼

A low coherence light beam is irradiated to the eyeball. A backward scattered light beam, which is reflected from each depth position in the eyeball, and a reference light beam, which is reflected from a mirror capable of moving, are caused to interfere with each other. A first backward scattered li

A low coherence light beam is irradiated to the eyeball. A backward scattered light beam, which is reflected from each depth position in the eyeball, and a reference light beam, which is reflected from a mirror capable of moving, are caused to interfere with each other. A first backward scattered light beam, which comes from the interface between the cornea and the anterior aqueous chamber, and a second backward scattered light beam, which comes from the interface between the anterior aqueous chamber and the crystalline lens, are thus separated accurately from each other. An optical absorbance of the anterior aqueous chamber (the aqueous humor) is calculated from the intensities of the two backward scattered light beams. Each of a plurality of low coherence light beams having different wavelengths is irradiated to the eyeball, and the aforesaid operation is repeated. The concentration of glucose in the aqueous humor is measured by utilizing near-infrared spectroscopy. The measurement is thus achieved non-invasively and accurately.

대표청구항 ▼

[ What is claimed is:] [1.] A glucose concentration measuring method, comprising the steps of:i) splitting a coherent light beam, which has been radiated out of a predetermined light source and the frequency of which is swept temporally in a sawtooth-like form, into a signal light beam and a referen

[ What is claimed is:] [1.] A glucose concentration measuring method, comprising the steps of:i) splitting a coherent light beam, which has been radiated out of a predetermined light source and the frequency of which is swept temporally in a sawtooth-like form, into a signal light beam and a reference light beam, each of which travels along one of two different optical paths,ii) irradiating said signal light beam to the eyeball lying at a predetermined position,iii) causing a first backward scattered light beam of said signal light beam, said first backward scattered light beam coming from an interface between the cornea and the anterior aqueous chamber of the eyeball, and said reference light beam to interfere with each other, said reference light beam being constituted of the coherent light beam, which has been radiated out of said light source with a difference in time in accordance with a difference between an optical path length of said signal light beam and said first backward scattered light beam and an optical path length of said reference light beam, and which has a difference in frequency with respect to said first backward scattered light beam, a first interference light beam being thereby obtained,iv) measuring an intensity of said first interference light beam,v) calculating an intensity of said first backward scattered light beam from the intensity of said first interference light beam,vi) causing a second backward scattered light beam of said signal light beam, said second backward scattered light beam coming from an interface between the anterior aqueous chamber and the crystalline lens of the eyeball, and said reference light beam to interfere with each other, said reference light beam being constituted of the coherent light beam, which has been radiated out of said light source with a difference in time in accordance with a difference between an optical path length of said signal light beam and said second backward scattered light beam and an optical path length of said reference light beam, and which has a difference in frequency with respect to said second backward scattered light beam, a second interference light beam being thereby obtained,vii) measuring an intensity of said second interference light beam,viii) calculating an intensity of said second backward scattered light beam from the intensity of said second interference light beam,ix) obtaining light absorption characteristics of constituents of the aqueous humor, which fills the anterior aqueous chamber, from the intensity of said first backward scattered light beam and the intensity of said second backward scattered light beam,x) obtaining light absorption characteristics of the constituents of the aqueous humor with respect to each of a plurality of other coherent light beams, which have wavelengths different from the wavelength of said coherent light beam, in the same manner, andxi) calculating a concentration of glucose in the constituents of the aqueous humor from the light absorption characteristics, which have been obtained with respect to the plurality of said coherent light beams.