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.

Abstract: Provided are an apparatus and a method for determining blood sugar level without blood using dark adaptation of the optic nerve, and a computer-readable recording medium storing a computer program performing the method. The apparatus irradiates stimulating light onto the pupil of a subject. A detecting device determines when the subject responds to the light. A calculator then calculates the blood sugar based on the response to the stimulating light.

Abstract: The present invention relates to a system and method for compensating for the effects of birefringence in a given sample and employs an optical birefringence analyzer to sense the real-time birefringence contributions and then provides a feedback signal to a compound electro-optical system that negates the birefringence contributions found in the given sample. The birefringence contribution vanishes, thus significantly reducing the main error component for polarimetric measurements.

Abstract: The present invention uses a high signal to noise ratio method and apparatus to analyze a characteristic of a biological object, such as blood glucose level. The method and apparatus can also have surgical applications, such as coagulation or ablation of a pattern on a biological object.

Abstract: A method and system for non-invasively measuring the concentration of an optically-active substance in a subject are provided. The system includes a light source adapted to transmit light towards a subject or object having a concentration of an optically-active substance, a polarizer positioned between the light source and the subject, an image capturing device, and a processor. The image capturing device is positioned to receive light reflected from the subject and create a measured image therefrom. The measured image defines measured light intensity data. The processor is configured to calculate a concentration of the optically-active substance based on a selected portion of the measured light intensity data.

Abstract: A measuring device (1) has, e.g., a voice input portion (27) for a measurer to input an arbitrary comment at a time of measurement, and it allows a voice recognition portion (28) to recognize the measurer's comment inputted by the voice input portion (27) and also allows a recognition result to be stored in a comment storing portion (43) in correlation with information on date and time, thereby storing conditions or the like of the measurer at the time of measurement, together with the measurement data.

Abstract: A non-invasive device for measuring blood glucose levels comprises an enclosure with a cover and dual openings, wherein the enclosure is covered with a transparent material (e.g., glass or plastic); at least two test cards arranged at specified distances and positioned within the enclosure; an illuminator and a conical light reflecting surface for casting a beam on the test cards. Light from one test card is reflected through one of the dual openings to sensing receptors of one eye. In order to enable the part of a diffuse beam reflected from the second test card made parallel within 10° to fall on the sensing receptors of the second eye, the enclosure is provided with a tubular prism covered with a closing plate having an opening at a first end while having an opening covered preferably with transparent material at a second end.

Abstract: The concentration of glucose in the anterior chamber of an eye is non-invasively measured by guiding a beam through a polarizer (4), a quarter wave plate (6), a polarization modulator (20), and an analyzer (7). After initializing the polarizer and the analyzer to extinguish the beam, it is guided parallel to the iris (56) of the eye (50) and introduced into the anterior chamber (57), wherein it is refracted, impinges on and is reflected from the iris, and exits the anterior chamber approximately collinear with the portion (55A) of the beam incident on the anterior chamber. The beam then is guided onto a detector (10), and a sufficient signal is applied to the polarization modulator to extinguish the beam. The signal represents the glucose concentration in the patient's blood.

Abstract: An ophthalmic lens comprising a receptor moiety can be used to determine the amount of an analyte in an ocular fluid. The receptor moiety can bind either a specific analyte or a detectably labeled competitor moiety. The amount of detectably labeled competitor moiety which is displaced from the receptor moiety by the analyte is measured and provides a means of determining analyte concentration in an ocular fluid, such as tears, aqueous humor, or interstitial fluid. The concentration of the analyte in the ocular fluid, in turn, indicates the concentration of the analyte in a fluid or tissue sample of the body, such as blood or intracellular fluid.

Abstract: The present invention is related to non-invasive methods and instruments to detect the level of analyte concentrations in the tissue of a subject by measuring electromagnetic radiation signatures from the subject's conjunctiva. The spectra of mid-infrared radiation emitted from a subject's body are altered corresponding to the concentration of various compounds within the radiating tissue. In one aspect of the invention, an instrument floods the conjunctiva of the subject with electromagnetic radiation in the mid-infrared range and measures analyte concentrations based on mid-infrared radiation reflected back to the instrument.

Abstract: The present invention is related to optical non-invasive methods and instruments to detect the level of analyte concentrations in the tissue of a subject. The spectra of mid-infrared radiation emitted from a subject's body are altered corresponding to the concentration of various compounds within the radiating tissue. In one aspect of the invention, an instrument floods a body surface of the subject, such as the subject's eye, with radiation in the mid-infrared range and measures analyte concentrations based on mid-infrared radiation reflected back to the instrument.

Abstract: Blood glucose concentrations are measured by non-invasive methods and apparatus using visual pigment bleaching in conjunction with psychophysical methodologies. Bleaching light of selected wavelengths is projected through the pupil of the eye of an observer onto the fundus to bleach visual pigments in the eye. The observer's psychophysical response to a visual stimulus is then measured to obtain information regarding the rate of regeneration of the visual pigments. From the rate of pigment regeneration, blood glucose concentrations are measured accurately. The psychophysical methodologies that may be used with the invention include visual acuity tests and color-matching tests.

Abstract: The determination of blood glucose in an individual is carried out by projecting illuminating light into an eye of the individual to illuminate the retina with the light having wavelengths that are absorbed by rhodopsin and with the intensity of the light varying in a prescribed temporal manner. The light reflected from the retina is detected to provide a signal corresponding to the intensity of the detected light, and the detected light signal is analyzed to determine the changes in form from that of the illuminating light. For a biased sinusoidal illumination, these changes can be expressed in terms of harmonic content of the detected light. The changes in form of the detected light are related to the ability of rhodopsin to absorb light and regenerate, which in turn is related to the concentration of blood glucose, allowing a determination of the relative concentration of blood glucose.

Abstract: There are many inventions described and illustrated herein. In one aspect, the present invention is a system and technique for non-invasively measuring, monitoring, inspecting, characterizing, determining and/or evaluating the blood glucose level in the aqueous humor of the eye of a patient (for example, a diabetic). In one embodiment, the present invention employs a plurality of wavelengths of light (for example, more than three) to measure, monitor, characterize, determine and/or evaluate the blood glucose level or concentration of a patient. The plurality of wavelengths of light may be directed into the aqueous humor of the eye and the reflected light (i.e., the light reflected by the eye) is detected and analyzed to provide information which is representative of the blood glucose level or concentration of the patient.

Abstract: The noninvasive measurement system provides a technique for manipulating wave data. In particular, wave data reflected from a biological entity is received, and the reflected wave data is correlated to a substance in the biological entity. The wave data may comprise light waves, and the biological entity may comprise a human being or blood. Additionally, a substance may comprise, for example, a molecule or ionic substance. The molecule may be, for example, a glucose molecule. Furthermore, the wave data is used to form a matrix of pixels with the received wave data. The matrix of pixels may be modified by techniques of masking, stretching, or removing hot spots. Then, the pixels may be integrated to obtain an integration value that is correlated to a glucose level. The correlation process may use a lookup table, which may be calibrated to a particular biological entity.

Abstract: An ophthalmic lens comprising a receptor moiety can be used to determine the amount of an analyte in an ocular fluid. The receptor moiety can bind either a specific analyte or a detectably labeled competitor moiety. The amount of detectably labeled competitor moiety which is displaced from the receptor moiety by the analyte is measured and provides a means of determining analyte concentration in an ocular fluid, such as tears, aqueous humor, or interstitial fluid. The concentration of the analyte in the ocular fluid, in turn, inidicates the concentration of the analyte in a fluid or tissue sample of the body, such as blood or intracellular fluid.

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.

Abstract: The present invention is related to optical non-invasive methods and instruments to detect the level of analyte concentrations in the tissue of a subject. The spectra of mid-infrared radiation emitted from a subject's body are altered corresponding to the concentration of various compounds within the radiating tissue. In one aspect of the invention, an instrument floods a body surface of the subject, such as the subject's eye, with radiation in the mid-infrared range and measures analyte concentrations based on mid-infrared radiation reflected back to the instrument.

Abstract: The present invention is related to optical non-invasive methods and instruments to detect the level of analyte concentrations in the tissue of a subject. The spectra of mid-infrared radiation emitted from a subject's body are altered corresponding to the concentration of various compounds within the radiating tissue. In one aspect of the invention, an instrument measures the level of mid-infrared radiation from the subject's body surface, such as the eye, and determines a specific analyte's concentration based on said analyte's distinctive mid-infrared radiation signature.

Abstract: An apparatus for measuring ocular and/or blood glucose levels comprises (a) an irradiating means (10) for irradiating light onto the eye (1) of a user from outside the cornea of the eye to excite an ocular glucose sensor in contact with an ocular fluid, said sensor being able to emit a total fluorescence having first and a second wavelength bands; (b) an optical path splitting means (11) for splitting said total fluorescence into a first fluorescence and a second fluorescence, said first fluorescence and said second fluorescence travelling along first and second optical paths; (c) a first detecting means (14) located in the first optical path; (d) a second detecting means (17) located in the second optical path; (e) a calculating means for calculating the intensity ratio or the first fluorecence to the second fluorescence and for determining an ocular glucose concentration in the ocular fluid; and (f) an arithmetic means for converting the ocular glucose concentration into a blood glucose concentration.

Abstract: The determination of blood glucose in an individual is carried out by projecting illuminating light into an eye of the individual to illuminate the retina with the light having wavelengths that are absorbed by rhodopsin and with the intensity of the light varying in a prescribed temporal manner. The light reflected from the retina is detected to provide a signal corresponding to the intensity of the detected light, and the detected light signal is analyzed to determine the changes in form from that of the illuminating light. For a biased sinusoidal illumination, these changes can be expressed in terms of harmonic content of the detected light. The changes in form of the detected light are related to the ability of rhodopsin to absorb light and regenerate, which in turn is related to the concentration of blood glucose, allowing a determination of the relative concentration of blood glucose.

Abstract: Blood glucose concentrations are measured by non-invasive methods and apparatus using visual pigment bleaching in conjunction with psychophysical methodologies. Bleaching light of selected wavelengths is projected through the pupil of the eye of an observer onto the fundus to bleach visual pigments in the eye. The observer's psychophysical response to a visual stimulus is then measured to obtain information regarding the rate of regeneration of the visual pigments. From the rate of pigment regeneration, blood glucose concentrations are measured accurately. The psychophysical methodologies that may be used with the invention include visual acuity tests and color-matching tests.

Abstract: The present invention uses a high signal to noise ratio method and apparatus to analyze a characteristic of a biological object, such as blood glucose level. The method and apparatus can also have surgical applications, such as coagulation or ablation of a pattern on a biological object.

Abstract: In one aspect, the present invention is directed to a glucose sensing device for implantation within subcutaneous tissue of an animal body. In one embodiment, the glucose sensing device includes a first chamber containing first magnetic particles and a hydrocolloid solution (for example, ConA-dextran hydrocolloid) wherein the first magnetic particles are dispersed in the hydrocolloid solution. In operation, glucose within the animal may enter and exit the first chamber and the hydrocolloid solution changes in response to the presence or concentration of glucose within the first chamber. The sensing device also includes a reference chamber containing second magnetic particles and a reference solution wherein the second magnetic particles are dispersed in the reference solution. The reference solution (for example, oil or alcohol compounds) includes a known or fixed viscosity. The reference solution may also be a hydrocolloid solution (for example, ConA-dextran hydrocolloid).

Abstract: The invention relates to a paste, which can undergo screen printing, for producing a porous polymer membrane. Said paste contains at least one polymer, one or more solvents for the polymer having a boiling point of >100° C., one or more non-solvents for the polymers (pore-forming agents) having a higher boiling point than that of the solvent(s), and contains a hydrophilic viscosity modifier.

Abstract: An ophthalmic lens comprising a receptor moiety can be used to determine the amount of an analyte in an ocular fluid. The receptor moiety can bind either a specific analyte or a detectably labeled competitor moiety. The amount of detectably labeled competitor moiety which is displaced from the receptor moiety by the analyte is measured and provides a means of determining analyte concentration in an ocular fluid, such as tears, aqueous humor, or interstitial fluid. The concentration of the analyte in the ocular fluid, in turn, inidicates the concentration of the analyte in a fluid or tissue sample of the body, such as blood or intracellular fluid.

Abstract: An apparatus (10) for determining a diagnostic glucose level in a human subject includes a light source (30) that produces collimated light at a selected wavelength. The collimated light is arranged such that it passes through a portion of an eye (12) of the subject and reflects off an eye lens (16) at a selected angle (&thgr;B) as reflected light. A polarization analyzer (70) measures a polarization of the reflected light that exits the eye (12). A path length processor (68) determines an optical path length (L&lgr;) of the reflected light within an aqueous humor (22) of the eye (12). A glucose level processor (90) computes a glucose concentration based on the measured polarization and the determined optical path length (L&lgr;).

Abstract: An ophthalmic lens comprising a receptor moiety can be used to determine the amount of an analyte in an ocular fluid. The receptor moiety can bind either a specific analyte or a detectably labeled competitor moiety. The amount of detectably labeled competitor moiety which is displaced from the receptor moiety by the analyte is measured and provides a means of determining analyte concentration in an ocular fluid, such as tears, aqueous humor, or interstitial fluid. The concentration of the analyte in the ocular fluid, in turn, indicates the concentration of the analyte in a fluid or tissue sample of the body, such as blood or intracellular fluid.

Abstract: Methods and systems for analyzing blood glucose readings comprising the steps of obtaining a plurality of blood glucose readings taken within a predetermined time category and time period, performing first calculations on said readings based on a predetermined normal range of glycemia in a first analysis and selecting and applying a pattern label having predetermined criteria to the plurality of blood glucose readings by comparing the results of the first calculations to the pattern label criteria.

Abstract: The determination of blood glucose in an individual is carried out by projecting illuminating light into an eye of the individual to illuminate the retina with the light having wavelengths that are absorbed by rhodopsin and with the intensity of the light varying in a prescribed temporal manner. The light reflected from the retina is detected to provide a signal corresponding to the intensity of the detected light, and the detected light signal is analyzed to determine the changes in form from that of the illuminating light. For a biased sinusoidal illumination, these changes can be expressed in terms of harmonic content of the detected light. The changes in form of the detected light are related to the ability of rhodopsin to absorb light and regenerate, which in turn is related to the concentration of blood glucose, allowing a determination of the relative concentration of blood glucose.

Abstract: The determination of blood glucose in an individual is carried out by projecting illuminating light into an eye of the individual to illuminate the retina with the light having wavelengths that are absorbed by rhodopsin and with the intensity of the light varying in a prescribed temporal manner. The light reflected from the retina is detected to provide a signal corresponding to the intensity of the detected light, and the detected light signal is analyzed to determine the changes in form from that of the illuminating light. For a biased sinusoidal illumination, these changes can be expressed in terms of harmonic content of the detected light. The changes in form of the detected light are related to the ability of rhodopsin to absorb light and regenerate, which in turn is related to the concentration of blood glucose, allowing a determination of the relative concentration of blood glucose.

Abstract: An ophthalmic lens comprising a receptor moiety can be used to determine the amount of an analyte in an ocular fluid. The receptor moiety can bind either a specific analyte or a detectably labeled competitor moiety. The amount of detectably labeled competitor moiety which is displaced from the receptor moiety by the analyte is measured and provides a means of determining analyte concentration in an ocular fluid, such as tears, aqueous humor, or interstitial fluid. The concentration of the analyte in the ocular fluid, in turn, indicates the concentration of the analyte in a fluid or tissue sample of the body, such as blood or intracellular fluid.

Abstract: A vacuum system for applying vacuum to the body cavity of a patient where a flow switch is provided that is located upstream of a vacuum regulator that can be adjusted to establish the level of vacuum desired to be applied to the patient. The flow switch provides an easy device for the caregiver to activate to fully and positively occlude the vacuum line to the patient. In one embodiment, the flow switch is constructed integral with a regulator having an rotatable actuator having a knob that is rotated to adjust the level of vacuum to the patient such the a caregiver can simply push the actuator knob inwardly to occlude the flow in the patient line and thereafter rotate the actuator knob to establish the desired level of vacuum to the patient.

Abstract: Methods and apparatuses for electrically connecting a medical glucose monitor to a glucose sensor set, as well as for testing the operation of the glucose monitor, monitor cable and glucose sensor set are provided. In one embodiment, an electric cable comprises a cable member, a first connector and a second connector. The cable member in turn comprises at least one insulated conductor, a conductive shielding layer disposed around the at least one insulated conductor; and an insulating layer disposed around the conductive shielding layer. A glucose monitoring system test plug provides for a releasable electrical connection with the electric cable. In one embodiment, the test plug comprises a housing and a fitting affixed thereto which is adapted to electrically couple the test plug with the electric cable.

Abstract: A method for determining blood glucose levels by measuring the glucose concentration in the ocular aqueous humor using optical refractometry by passing laser light the aqueous ocular humor, measuring the laser light's optical refractivity, and comparing the refractivity with known data, the comparison yielding the blood glucose level.

Abstract: A system for testing for the existence of a biomedical condition of an animal test subject having first and second devices for projecting radiant energy. The first device for projecting radiant energy projects a beam of radiant energy into and through the tissue of a portion of the animal test subject. The second device for projecting radiant energy is implanted in the body of the animal test subject and projects a second beam of radiant energy out of the body in response to the projected radiation of the first radiant energy source. The second device for projecting radiant energy can be a mirror that reflects the first beam of radiant energy or it can be a source of radiant energy, such as a vertical-cavity surface-emitting laser, that emits a specific wavelength of light when activated by the first device for projecting radiant energy. A detector positioned outside the body and relative to the second device for projecting radiant energy detects the second beam of radiant energy.

Abstract: A non-invasive method for determining blood level of an analyte of interst, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

Abstract: Methods and apparatuses for electrically connecting a medical glucose monitor to a glucose sensor set, as well as for testing the operation of the glucose monitor, monitor cable and glucose sensor set are provided. In one embodiment, an electric cable comprises a cable member, a first connector and a second connector. The cable member in turn comprises at least one insulated conductor, a conductive shielding layer disposed around the at least one insulated conductor; and an insulating layer disposed around the conductive shielding layer. A glucose monitoring system test plug provides for a releasable electrical connection with the electric cable. In one embodiment, the test plug comprises a housing and a fitting affixed thereto which is adapted to electrically couple the test plug with the electric cable.

Abstract: A polarimeter adapted for measurement of the concentration of glucose in a sample includes a laser beam passing through a first polarizer and an optical modulator and split into a measurement beam passing through a FIRST ANALYZER to a first detector coupled to a first amplifier and a reference beam passing through a SECOND ANALYZER to a second detector coupled to a second amplifier. Identical multiple filtering and summing operations are performed on outputs of the first and second amplifiers to produce a first &PSgr;2/2 signal and a first 2&bgr;&PSgr; signal in response to the measurement beam and a second &PSgr;2/2 signal and a second 2&bgr;&PSgr; signal in response to the reference beam. The measurement beam is stabilized by comparing the second &PSgr;2/2 signal to a first reference signal to produce a first error signal and comparing the second 2&bgr;&PSgr; signal to a second reference signal to produce a second error signal.

Abstract: A subcutaneous glucose sensor comprising an infrared emitter which transmits light through a narrow sample of interstitial fluid held in a light transparent sample trough. The sensor can be incorporated with an insulin pump in order to create an insulin delivery and feedback measurement loop system.

Abstract: An ophthalmic lens comprising a receptor moiety can be used to determine the amount of an analyte in an ocular fluid. The receptor moiety can bind either a specific analyte or a detectably labeled competitor moiety. The amount of detectably labeled competitor moiety which is displaced from the receptor moiety by the analyte is measured and provides a means of determining analyte concentration in an ocular fluid, such as tears, aqueous humor, or interstitial fluid. The concentration of the analyte in the ocular fluid, in turn, indicates the concentration of the analyte in a fluid or tissue sample of the body, such as blood or intracellular fluid.

Abstract: An ophthalmic lens comprising a receptor moiety can be used to determine the amount of an analyte in an ocular fluid. The receptor moiety can bind either a specific analyte or a detectably labeled competitor moiety. The amount of detectably labeled competitor moiety which is displaced from the receptor moiety by the analyte is measured and provides a means of determining analyte concentration in an ocular fluid, such as tears, aqueous humor, or interstitial fluid. The concentration of the analyte in the ocular fluid, in turn, indicates the concentration of the analyte in a fluid or tissue sample of the body, such as blood or intracellular fluid.

Abstract: The concentration of glucose in the anterior chamber of an eye is non-invasively measured by guiding a beam through a polarizer (4), a quarter wave plate (6), a polarization modulator (20), and an analyzer (7). After initializing the polarizer and the analyzer to extinguish the beam, it is guided parallel to the iris (56) of the eye (50) and introduced into the anterior chamber (57), wherein it is refracted, impinges on and is reflected from the iris, and exits the anterior chamber approximately collinear with the portion (55A) of the beam incident on the anterior chamber. The beam then is guided onto a detector (10), and a sufficient signal is applied to the polarization modulator to extinguish the beam. The signal represents the glucose concentration in the patient's blood.

Abstract: The concentration of glucose in the anterior chamber of an eye is non-invasively measured by guiding a beam through a polarizer (4), a quarter wave plate (6), a polarization modulator (20), and an analyzer (7). After initializing the polarizer and the analyzer to extinguish the beam, it is guided parallel to the iris (56) of the eye (50) and introduced into the anterior chamber (57), wherein it is refracted, impinges on and is reflected from the iris, and exits the anterior chamber approximately collinear with the portion (55A) of the beam incident on the anterior chamber. The beam then is guided onto a detector (10), and a sufficient signal is applied to the polarization modulator to extinguish the beam. The signal represents the glucose concentration in the patient's blood.

Abstract: The intensities of backscattering light generated by predetermined interfaces of an eyeball when a laser beam emitted from a semiconductor laser is projected onto the eyeball in a predetermined position are detected. The absorbance or refractive index of the aqueous humor in the anterior chamber of the eyeball is determined on the basis of the intensities of the backscattering light, and the glucose concentration in the aqueous humor is determined on the basis of the absorbance or refractive index of the aqueous humor in the anterior chamber thus determined. An extinction filter is disposed on the optical path of the laser beam between the semiconductor laser and the eyeball so that the intensity of the laser beam entering the eyeball is reduced not higher than a predetermined value of MPE.

Abstract: A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

Abstract: A light beam, which has been radiated out of a predetermined light source, is irradiated to the eyeball lying at a predetermined position. Each of intensity values of first and second backward scattered light beams of the light beam having been irradiated to the eyeball is detected. The first backward scattered light beam comes from an interface between the cornea of the eyeball and the ambient air, and the second backward scattered light beam comes from an interface between the cornea and the anterior aqueous chamber of the eyeball. A refractive index of the aqueous humor, which fills the anterior aqueous chamber, is calculated from the intensity values of the first and second backward scattered light beams.

Abstract: A system and method for determining a duration that a patient has been experiencing a medical condition compares characteristics of fluorescent emissions from a target tissue to expected characteristics. In a system and method embodying the invention, a target tissue is illuminated with excitation light, and fluorescent emissions generated by the target tissue in response to the excitation light are detected. Different characteristics of the fluorescent emissions, including the fluorescent emission intensity or the fluorescent lifetime may be determined. The determined characteristics of the detected fluorescent emissions are then compared to expected characteristics of the fluorescent emissions. The amount that the detected fluorescent characteristics deviate from the expected fluorescent characteristics is used to determine a duration that a patient has been experiencing a medical condition. In some instances, the backscattered portions of the excitation light may also be used to make the determination.

Abstract: 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.

Abstract: Relative directions of excitation and photoreceiving optical systems are so set that an angle formed by optical axes thereof in the air is 14.degree., and an eyeball is fixed in such a direction that its ocular axis divides the angle formed by the optical axes into two equal parts. On a light incidence side of a one-dimensional solid-state image pickup device of the photoreceiving optical system, a slit is arranged for inputting measuring light components generated from portions of the eyeball having different depth positions on an excitation light beam in photoelectric conversion elements of different positions of the image pickup device.