Non-invasive glucose-meter
First Claim
1. A method of determining the concentration of a substance in an eye, the eye having a cornea, a pupil, an iris, a lens, a liquid, and a retina, the method comprising:
- providing a measurement light beam having a first wavelength at which the substance has a non-zero first absorption coefficient;
providing a reference light beam having a second wavelength at which the substance has a second absorption coefficient which is substantially equal to zero;
irradiating the retina with the measurement light beam, thereby passing the measurement light beam through the cornea, the pupil, the lens, and the liquid;
irradiating the retina with the reference light beam, thereby passing the reference light beam through the cornea, the pupil, the lens, and the liquid;
reflecting at least a portion of the measurement light beam from the retina and through the liquid, the lens, the pupil, and the cornea, thereby producing a measurement retro-reflected light beam having the first wavelength;
reflecting at least a portion of the reference light beam from the retina and through the liquid, the lens, the pupil, and the cornea, thereby producing a reference retro-reflected light beam having the second wavelength;
providing a detector adapted to generate a measurement signal in response to being irradiated by light having the first wavelength and to generate a reference signal in response to being irradiated by light having the second wavelength;
irradiating the detector with the measurement retro-reflected light beam;
irradiating the detector with the reference retro-reflected light beam; and
determining the concentration of the substance in the eye in response to the measurement signal and the reference signal from the detector.
5 Assignments
0 Petitions
Accused Products
Abstract
An apparatus for measuring a concentration of a substance in an eye (13) having a retina (17) includes a measurement light source (4) producing a measurement light beam having a first wavelength at which the substance has a non-zero first absorption coefficient. The apparatus further includes a reference light source (6) producing a reference light beam having a second wavelength at which the substance has a second absorption coefficient which is substantially equal to zero. The apparatus further includes an optical combiner (1) which is positionable so that at least a portion of the measurement light beam retro-reflects from the retina (17) and so that at least a portion of the reference light beam retro-reflects from the retina (17). The apparatus further includes a detector (9) positionable to receive the retro-reflected measurement light beam and the retro-reflected reference light beam. The detector (9) is responsive to light having the first wavelength by generating a measurement signal and responsive to light having the second wavelength by generating a reference signal. The apparatus further includes an electrical circuit coupled to the detector (9). The electrical circuit is responsive to the measurement signal and the reference signal to measure the concentration of the substance in the eye (13).
16 Citations
21 Claims
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1. A method of determining the concentration of a substance in an eye, the eye having a cornea, a pupil, an iris, a lens, a liquid, and a retina, the method comprising:
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providing a measurement light beam having a first wavelength at which the substance has a non-zero first absorption coefficient;
providing a reference light beam having a second wavelength at which the substance has a second absorption coefficient which is substantially equal to zero;
irradiating the retina with the measurement light beam, thereby passing the measurement light beam through the cornea, the pupil, the lens, and the liquid;
irradiating the retina with the reference light beam, thereby passing the reference light beam through the cornea, the pupil, the lens, and the liquid;
reflecting at least a portion of the measurement light beam from the retina and through the liquid, the lens, the pupil, and the cornea, thereby producing a measurement retro-reflected light beam having the first wavelength;
reflecting at least a portion of the reference light beam from the retina and through the liquid, the lens, the pupil, and the cornea, thereby producing a reference retro-reflected light beam having the second wavelength;
providing a detector adapted to generate a measurement signal in response to being irradiated by light having the first wavelength and to generate a reference signal in response to being irradiated by light having the second wavelength;
irradiating the detector with the measurement retro-reflected light beam;
irradiating the detector with the reference retro-reflected light beam; and
determining the concentration of the substance in the eye in response to the measurement signal and the reference signal from the detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for measuring a concentration of a substance in an eye having a retina, the apparatus comprising:
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a measurement light source producing a measurement light beam having a first wavelength, the substance having a non-zero first absorption coefficient for light at the first wavelength;
a reference light source producing a reference light beam having a second wavelength, the substance having a second absorption coefficient which is substantially equal to zero for light at the second wavelength;
an optical combiner comprising a dichroic coating layer, the optical combiner positionable so that at least a portion of the measurement light beam retro-reflects from the retina and so that at least a portion of the reference light beam retro-reflects from the retina;
a detector positionable to receive the retro-reflected measurement light beam and the retro-reflected reference light beam, the detector responsive to light having the first wavelength by generating a measurement signal and responsive to light having the second wavelength by generating a reference signal; and
an electrical circuit coupled to the detector, the electrical circuit responsive to the measurement signal and the reference signal to measure the concentration of the substance in the eye. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification