Method and apparatus for non-invasive glucose sensing through the eye

• US 6,885,882 B2
• Filed: 05/27/2003
• Issued: 04/26/2005
• Est. Priority Date: 05/28/2002
• Status: Expired due to Term

• Current Assignee: Coté, Gerard L., Justin S. Baba
• Original Assignee: Coté, Gerard L., Justin S. Baba
• Inventors: Baba, Justin S., Coté, Gerard L.
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US10/445,648
• Publication Number:
  US 20030225321A1
• Time in Patent Office: 700 Days
• Field of Search: 600/310, 600/316, 600/318, 600/319, 356/364, 356/368, 356/369
• US Class Current: 600/319
• CPC Class Codes: A61B 3/0008 provided with illuminating means A61B3/117 takes precedence; goniolenses used for laser treatment A61F9/009; illuminating means for optical instruments G02B27/00
• 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 5/14507 specially adapted for measuring characteristics of body fluids other than blood devices for taking samples of body liquids A61B10/0045
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14558 by polarisation
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: G01N 2021/217 Measuring depolarisation or comparing polarised and depolarised parts of light
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/23 Bi-refringence
• CPC Class Codes: G01N 21/39 using tunable lasers
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers
• CPC Class Codes: G01N 2201/0627 Use of several LED's for spectral resolution
• CPC Class Codes: G01N 2201/067 Electro-optic, magneto-optic, acousto-optic elements

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.

Claims

1. A system for sensing an analyte in the aqueous humor of the eye of a patient, the system comprising:

a light source unit to provide at least three light beams wherein each light beam includes a wavelength and modulation frequency that is different from the other light beams;

a polarization mechanism, optically positioned to receive the light beams, and to linearly polarize each light beam;

a detector unit, optically positioned to receive the light beams reflected by the eye, to detect a change in polarization of the light beams, wherein the polarization of the light beams are changed as a result of contact with analyte in the aqueous humor of the eye; and

a processing unit, coupled to the detector unit, to determine the concentration of analyte in the aqueous humor of the eye using information which is representative of the change in polarization of the light beams.

2. The system of claim 1 wherein the light source unit includes a plurality of lasers.

3. The system of claim 1 wherein each light beam is linearly polarized at any angle.

4. The system of claim 1 wherein the polarization mechanism is a polarization rotator.

5. The system of claim 4 wherein the polarization rotator feeds back an output voltage proportional to the fundamental harmonic of the light beam.

6. The system of claim 5 wherein the polarization rotator is a faraday rotator.

7. The system of claim 1 wherein the polarization mechanism modulates the polarization vector of at least two of the light beams.

8. The system of claim 7 wherein the polarization rotator is a faraday rotator.

9. The system of claim 1 further including a beam steering mechanism to direct the beams through the anterior chamber of the eye of the patient.

10. The system of claim 9 wherein the beam steering mechanism is an electro-optic device.

11. The system of claim 10 wherein the electro-optic device is a piezo-electric mirror.

12. A system for sensing an analyte in the aqueous humor of the eye of a patient, the system comprising:

a light source unit to provide at least three light beams wherein each light beam includes a wavelength and modulation frequency that is different from the other light beams;

a polarization mechanism, optically positioned to receive the light beams, and to linearly polarize each light beam;

a beam steering mechanism, optically positioned to receive linearly polarized light beams, that is capable of directing the linearly polarized light beams through the anterior chamber of the eye of the patient;

an image tracking unit, coupled to the beam steering mechanism, to control the beam steering mechanism in response to motion of the eye of the patient;

a detector unit, optically positioned to receive the light beams reflected by the eye, to detect a change in polarization of the light beams, wherein the polarization of the light beams are changed as a result of contact with analyte in the aqueous humor of the eye; and

a processing unit, coupled to the detector unit, to determine the concentration of analyte in the aqueous humor of the eye using information which is representative of the change in polarization of the light beams.

13. The system of claim 12 wherein the light source unit includes a plurality of lasers.

14. The system of claim 12 wherein each light beam is linearly polarized at any angle.

15. The system of claim 12 wherein the polarization mechanism is a polarization rotator.

16. The system of claim 15 wherein the polarization rotator feeds back an output voltage proportional to the fundamental harmonic of the light beam.

17. The system of claim 16 wherein the polarization rotator is a faraday rotator.

18. The system of claim 12 wherein the polarization mechanism modulates the polarization vector of at least two of the light beams.

19. The system of claim 12 wherein the beam steering mechanism is an electro-optic device.

20. The system of claim 19 wherein the electro-optic device is a piezo-electric mirror.