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 nearly parallel measurement light beam having a first wavelength at which the substance has a non-zero first absorption coefficient;
providing a nearly parallel 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, the detector located at a distance of at least 100 mm from the eye;
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) 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. At least a portion of the measurement light beam retro-reflects from the retina (17) and at least a portion of the reference light beam retro-reflects from the retina (17). The apparatus further includes a detector (9) 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.
66 Citations
23 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 nearly parallel measurement light beam having a first wavelength at which the substance has a non-zero first absorption coefficient; providing a nearly parallel 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, the detector located at a distance of at least 100 mm from the eye; 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, 10)
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11. 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 nearly parallel 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 nearly parallel 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 while the detector is located at a distance of at least 100 mm from the eye, 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 (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An apparatus for measuring a concentration of a substance in an eye, the eye having a cornea, a pupil, an iris, a lens, a liquid, and a retina, the apparatus comprising:
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means for providing a nearly parallel measurement light beam having a first wavelength at which the substance has a non-zero first absorption coefficient; means for providing a nearly parallel reference light beam having a second wavelength at which the substance has a second absorption coefficient which is substantially equal to zero; means for irradiating the retina with the measurement light beam, thereby passing the measurement light beam through the cornea, the pupil, the lens, and the liquid, wherein at least a portion of the measurement light beam is reflected 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; means for irradiating the retina with the reference light beam, thereby passing the reference light beam through the cornea, the pupil, the lens, and the liquid, wherein at least a portion of the reference light beam is reflected 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; means for generating a measurement signal in response to the measurement retro-reflected light beam and for generating a reference signal in response to the reference retro-reflected light beam while the generating means is located at a distance of at least 100 mm from the eye; and means for determining the concentration of the substance in the eye in response to the measurement signal and the reference signal.
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Specification