Non-Invasive Ocular Analyte Sensing System

• US 20140364709A1
• Filed: 08/27/2014
• Published: 12/11/2014
• Est. Priority Date: 10/07/2009
• Status: Active Grant

• Current Assignee: University of Toledo
• Original Assignee: University of Toledo
• Inventors: Cameron, Brent D., Webb, Anthony J.
• Granted Patent: US 9,456,772 B2
• Time in Patent Office: Days
• US Class Current: 600/319
• CPC Class Codes: A61B 3/10 Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14558 by polarisation

Abstract

A noninvasive method and apparatus for determining analyte concentration (e.g., glucose) in a subject that includes measuring light refraction from at least a portion one or more structures. One example of such structure is the subject'"'"'s iris.

Claims

1. An apparatus for measuring the concentration of glucose in an eye, the apparatus comprising:

an energy source capable of emitting at least one beam of non-collimated light at varying intensities; and

a data capturing module configured to (i) receive data generated by the interaction of the non-collimated light with one or more fiducial markers in an eye, and (ii) correlate the data with a level of glucose in the eye.

2. The apparatus of claim 1, wherein the energy source is a bimodal light source configured to generate at least one stimulus wavelength of light and at least one illumination wavelength of light.

3. The apparatus of claim 2, wherein the illumination wavelength of light is in the visible to near-infrared region.

4. The apparatus of claim 2, wherein the stimulus wavelength of light is a blue-green light.

5. The apparatus of claim 2, wherein the bimodal light source is configured to generate the stimulus wavelength of light at varying intensities.

6. The apparatus of claim 2, wherein the bimodal light source utilizes optical powers in the microwatt range.

7. The apparatus of claim 1, wherein the energy source comprises one or more light-emitting diodes (LEDs).

8. The apparatus of claim 1, wherein the data capturing module includes an image capturing device.

9. The apparatus of claim 1, further comprising at least one beam splitter configured to reflect at least one beam toward the eye.

10. The apparatus of claim 1, further comprising at least one light filter.

11. The apparatus of claim 10, wherein at least one light filter is selected from the group consisting of a notch filter, a band pass filter, and a combination of short- and long-pass filters.

12. The apparatus of claim 1, further comprising a polarization controller.

13. The apparatus of claim 12, wherein the polarization controller is selected from the group consisting of a linear polarizer;

a polarizer and a waveplate;

a polarizer and a variable retarder;

a polarizer and a Faraday component;

a polarizer and a photoelastic modulator; and

a combination thereof.

14. The apparatus of claim 12, further comprising a beam splitter, wherein the polarization controller is configured between the beam splitter and the energy source.

15. The apparatus of claim 14, further comprising a camera, a light filter, and a second polarization controller disposed between the camera and the light filter.

16. A method of enhancing images of an eye, the method comprising illuminating an eye with a uniform irradiance profile and stimulating the eye by glancing angle delivery of a light source, so as to enhance images of the eye.

17. A method of determining glucose concentration in an eye comprising:

illuminating an eye with a near-infrared wavelength;

exposing the eye to a light protocol, wherein the light protocol comprises a blue-green wavelength of light to stimulate a pupillary light reflex of the eye;

correlating the reflex of the eye in response to the light protocol to glucose concentration in the eye.

18. The method of claim 17, wherein the correlating comprises:

correlating optical signals from one or more fiducial markers in the eye to the optical refractive index of the aqueous humor of the eye; and

correlating the optical refractive index of the aqueous humor to the concentration of glucose in the aqueous humor.

19. The method of claim 17, wherein the eye is an animal eye.

20. The method of claim 17, wherein the eye is a human eye.