Blood glucose levels of a person are determined by a device which provides a changing light pattern which changes in regard to one or several parameters defining its luminance, color, rate of flicker, spatial contrast, detail content, speed or otherwise provided that the change gradually stimulates one retinal system more than another retinal system. A person observes the changing light pattern until a subjective visual effect occurs, which is preferably an observer perceived dramatic change in the appearance of the light pattern, for example a change in the perceived direction of rotation. The subjective visual effect indicates a specific ratio of stimulation of the two retinal systems, for example the point of balanced stimulation of the two systems. Upon noting the subjective visual effect the patient actuates a mechanism which takes note of the current light pattern parameter values, allowing the device to relate such parameter values with a corresponding blood glucose level using predetermined calibration data. Thereby, the person's glucose level is accurately determined in a completely non-invasive manner.
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.degree. 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.
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.
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.
Blood glucose levels of a person are determined by a device which provides a light pattern which varies in regard to one or several parameters defining its luminance, color, rate of flicker, spatial contrast, detail content, speed or otherwise provided that the pattern has first and second appearances and can be shifted from one appearance to the other by changing one or more parameters. A person observes the light pattern and a subjective visual effect which correlates with a corresponding blood glucose level. Thus, the person's glucose level is accurately determined in a completely non-invasive manner.
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 (.theta..sub.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.sub..lambda.) 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.sub..lambda.).
