Apparatus and method for optical measurements

• US 7,896,498 B2
• Filed: 03/30/2009
• Issued: 03/01/2011
• Est. Priority Date: 03/30/2009
• Status: Active Grant

• Current Assignee: Ottawa Hospital Research Institute (Ottawa Hospital)
• Original Assignee: Ottawa Hospital Research Institute (Ottawa Hospital)
• Inventors: Lagali, Neil, Munger, Rejean
• Primary Examiner(s): Dinh; Jack
• Application Number:
  US12/414,437
• Publication Number:
  US 20100245764A1
• Time in Patent Office: 701 Days
• Field of Search: 351/200, 351/205, 351/206, 351/213, 351/214, 351/215, 351/221, 351/246
• US Class Current: 351/221
• 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 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/14555 specially adapted for the eye fundus
• CPC Class Codes: A61B 5/14558 by polarisation

Abstract

Disclosed are an apparatus and method for separately detecting and measuring specularly reflected light and diffusely reflected light following illumination of an eye by light. The apparatus and method of the present invention facilitates substantial separation of the diffusely reflected light from light specularly reflected from the eye after passing through one or more elements of the eye, for example, the cornea, lens, retinal vasculature, the nerve fibre layer and/or the photoreceptors. The collection of these separate streams of independent optical signals to appropriate detection systems provides specificity and accuracy in determination of optical properties of one or more elements of the eye.

Claims

1. An optical apparatus, comprising:

(a) an illumination system comprising a light source for illuminating one or more elements of an eye of a subject;

(b) an optical separation means for separating light specularly reflected from one or more component of said eye from diffusely reflected light returned from said eye;

(c) a detection system comprising;

(i) one or more detectors; and

(ii) transmission means for collecting and separately transmitting the separated specularly reflected light and the diffusely reflected light to said one or more detector, and

(d) an eye/instrument interface for controlling light delivery from said illumination system to said eye and for capturing and transmitting light exiting the eye to said detection system.

2. The optical apparatus according to claim 1, wherein said optical separation means includes optical components in the illumination system, the detection system or both.

3. The optical apparatus according to claim 1 or 2 additionally comprising means for modifying the light source.

4. The optical apparatus according to claim 3, wherein said means for modifying the light source modifies the vergence, spectral properties, polarization, and/or intensity of said light source.

5. The optical apparatus according to claim 1 or 2, wherein said light source comprises a tungsten-halogen lamp, an incandescent lamp, an arc lamp, a light emitting diode, a laser, or any combination thereof.

6. The optical apparatus according to claim 2, wherein said optical separation means comprises an optical element in said detection system positioned at the image point of the specularly reflected light for collecting and transmitting the specularly reflected light to one of said one or more detectors in said detection system.

7. The optical apparatus according to claim 6, wherein said optical element is a focusing mirror, a lens, a blocking aperture, a flat mirror, a prism, or a combination thereof.

8. The optical apparatus according to claim 1 additionally comprising one or more optical filters.

9. The optical apparatus according to claim 1, wherein the detection system comprises more than one detector.

10. The optical apparatus according to claim 1, wherein at least one of said one or more detectors is a photodiode, a camera, a spectrometer or a bolometer.

11. The optical apparatus according to claim 1, wherein said detection system simultaneously measures the specularly reflected light and the diffusely reflected light.

12. The optical apparatus according to claim 1, wherein said detection system sequentially measures the specularly reflected light and the diffusely reflected light.

13. A method for monitoring light remitted from an eye of a subject comprising the steps of:

(a) illuminating one or more element of said eye with a light source;

(b) transmitting light specularly reflected from said eye to a detection system via an optical separation means; and

(c) separately transmitting diffusely reflected light remitted from said eye to said detection system.

14. The method according to claim 13, wherein said detection system comprises one or more detectors.

15. The method according to claim 14, wherein at least one of said one or more detectors is a photodiode, a camera, a spectrometer or a bolometer.

16. The method according to claim 13, wherein said detection system simultaneously measures the specularly reflected light and the diffusely reflected light.

17. The method according to claim 13, wherein said detection system sequentially measures the specularly reflected light and the diffusely reflected light.

18. The method according to claim 13, additionally comprising the step of transmitting said diffusely reflected light to a camera.

19. The method according to claim 13, wherein said diffusely reflected light is transmitted to said camera to obtain an image of the illumination spot on the retina of said eye and wherein said method additionally comprises the step of adjusting said illumination spot.

20. The method according to claim 13 for monitoring the health of said subject.

21. The method according to claim 13 for monitoring the health of the retina of said subject.