Methods and apparatus for retinal imaging

• US 9,060,718 B2
• Filed: 02/13/2013
• Issued: 06/23/2015
• Est. Priority Date: 02/13/2012
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Raskar, Ramesh, Lawson, Matthew Everett, Boggess, Jason, Khullar, Siddharth
• Primary Examiner(s): Sugarman, Scott J
• Assistant Examiner(s): Alexander, William R
• Application Number:
  US13/766,751
• Publication Number:
  US 20130208241A1
• Time in Patent Office: 860 Days
• Field of Search: 351/205, 351/206, 351/246
• US Class Current: 1/1
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/0091 Fixation targets for viewing direction
• CPC Class Codes: A61B 3/12 for looking at the eye fundus, e.g. ophthalmoscopes A61B3/13 takes precedence
• CPC Class Codes: A61B 3/14 Arrangements specially adapted for eye photography apparatus or arrangements for taking photographs per se G03B
• CPC Class Codes: G06V 40/19 Sensors therefor

Abstract

In exemplary implementations, this invention comprises apparatus for retinal self-imaging. Visual stimuli help the user self-align his eye with a camera. Bi-ocular coupling induces the test eye to rotate into different positions. As the test eye rotates, a video is captured of different areas of the retina. Computational photography methods process this video into a mosaiced image of a large area of the retina. An LED is pressed against the skin near the eye, to provide indirect, diffuse illumination of the retina. The camera has a wide field of view, and can image part of the retina even when the eye is off-axis (when the eye'"'"'s pupillary axis and camera'"'"'s optical axis are not aligned). Alternately, the retina is illuminated directly through the pupil, and different parts of a large lens are used to image different parts of the retina. Alternately, a plenoptic camera is used for retinal imaging.

Claims

1. A method of imaging a retina of a first eye of a human, which method comprises, in combination:

(a) using a camera to capture multiple images of different areas of the retina during a time period in which the first eye rotates through different rotational positions;

(b) using one or more processors to process the multiple images to create a mosaiced image of a region of the retina; and

(c) using one or more light sources to provide indirect, diffuse illumination of the retina, which illumination passes through at least skin and sclera of the human before reaching the retina.

2. The method of claim 1, wherein:

(a) the one or more light sources comprise a plurality of light sources; and

(b) the method further comprises positioning each of the plurality of light sources, respectively, at a different location adjacent to facial skin of the human while providing the illumination.

3. A method of imaging a retina of a first eye of a human, which method comprises, in combination:

(a) using a camera to capture multiple images of different areas of the retina during a time period in which the first eye rotates through different rotational positions;

(b) using one or more processors to process the multiple images to create a mosaiced image of a region of the retina; and

(c) using an electronic screen to display moving visual stimuli to a second eye of the human, which stimuli (i) induce the second eye to rotate as the second eye tracks the stimuli and (ii) by bi-ocular coupling, induce the first eye to also rotate.

4. The method of claim 3, wherein the method further comprises using the electronic screen to display real-time visual feedback to a second eye of the human, which feedback is indicative of the optical axis of the camera and the pupillary axis of the first eye.

5. Apparatus comprising, in combination:

(a) a camera, which camera is configured to capture multiple images of different areas of the retina of a first eye of a human during a time period in which the first eye rotates through different rotational positions;

(b) one or more processors, which one or processors are configured to process the multiple images to create a mosaiced image of a region of the retina; and

(c) one or more light sources, which light sources are configured to provide indirect, diffuse illumination of the retina, which illumination passes through at least skin and sclera of the human before reaching the retina.

6. The apparatus of claim 5, wherein:

(a) the one or more light sources comprise a plurality of light sources; and

(b) each of the plurality of light sources, respectively, is configured to be positioned at a different location adjacent to facial skin of the human while providing the illumination.

9. The apparatus of claim 5, wherein the light sources are configured to sequentially illuminate the retina with different wavelengths of light at different times, respectively, while the camera captures synchronized images.

7. Apparatus comprising, in combination:

(a) a camera, which camera is configured to capture multiple images of different areas of the retina of a first eye of a human during a time period in which the first eye rotates through different rotational positions;

(b) one or more processors, which one or processors are configured to process the multiple images to create a mosaiced image of a region of the retina; and

(c) an electronic screen

that is configured to display moving visual stimuli to a second eye of the human, which stimuli (i) induce the second eye to rotate as the second eye tracks the stimuli and (ii) by bi-ocular coupling, induce the first eye to also rotate.

8. The apparatus of claim 7, wherein

the electronic screen is configured to display real-time visual feedback to a second eye of the human, which feedback is indicative of the optical axis of the camera and the pupillary axis of the first eye.