Methods and apparatus for retinal imaging

• US 9,295,388 B2
• Filed: 03/16/2014
• Issued: 03/29/2016
• Est. Priority Date: 02/13/2012
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Lawson, Matthew Everett, Raskar, Ramesh
• Primary Examiner(s): Won, Bumsuk
• Assistant Examiner(s): Alexander, William R
• Application Number:
  US14/214,950
• Publication Number:
  US 20140226128A1
• Time in Patent Office: 744 Days
• Field of Search: 351/200
• 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) a camera capturing multiple images of different areas of the retina during a time period in which the first eye rotates through different rotational positions; and

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

wherein

(i) a lens that is exterior to and not part of the first eye includes a first region of the lens and a second region of the lens, and

(ii) the method includes

(A) when the eye is in a first rotational position, the camera capturing a first image of a first area of the retina but not a second area of the retina, such that light forming the first image passes through the pupil of the first eye and travels through the first region but not the second region of the lens, and

(B) when the eye is in a second rotational position, the camera capturing a second image of the second area but not the first area of the retina, such that light forming the second image passes through the pupil of the eye and travels through the second region but not the first region of the lens,

(iii) the first and second rotational positions are different from each other, and

(iv) the multiple images include the first and second images.

2. The method of claim 1, wherein the method further comprises causing a light source that illuminates the retina to undergo a movement, relative to the human'"'"'s head as a whole, during the time period.

3. The method of claim 2, wherein the movement comprises physical translation of the light source, which light source emits and does not merely reflect light.

4. The method of claim 1, wherein:

(a) the light forming the first image includes light that impacts a sensor of the camera when traveling along the optical axis of the camera; and

(b) the light forming the second image does not include light that impacts a sensor of the camera when traveling along the optical axis of the camera.

5. The method of claim 2, wherein the movement comprises turning on and off different light sources in an array of light sources.

6. The method of claim 2, wherein the movement comprises moving or otherwise changing one or more optical elements that guide light from the light source.

7. The method of claim 2, wherein the movement occurs while a sensor of the camera is motionless relative to the subject'"'"'s head, as a whole.

8. The method of claim 2, wherein the movement occurs while a housing of the camera is motionless relative to the subject'"'"'s head, as a whole.

9. The method of claim 1, wherein the method further comprises using the one or more processors to control movement of a light source that illuminates the first eye, based on movement of visual stimuli presented to a second eye of the human.

10. The method of claim 1, wherein the method further comprises using the one or more processors to control movement of visual stimuli presented to a second eye of the human, based on movement of a light source that illuminates the first eye.

11. The method of claim 1, wherein:

(a) a light source illuminates the retina; and

(b) the location of the light source changes during the time period.

12. The method of claim 1, wherein:

(a) a light source illuminates the retina; and

(b) movement of the light source compensates for rotation of the first eye during the time period.

13. The method of claim 1, wherein:

(a) a light source illuminates the retina;

(b) the light source has an aperture; and

(c) the aperture has a static shape, the static shape being that of a motion path indicated by bi-ocular stimulus during the time period.

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

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

(b) one or more processors

(i) processing the multiple images to create a mosaiced image of a region of the retina; and

(ii) controlling movement of a light source that illuminates the first eye, based on movement of visual stimuli presented to a second eye of the human.

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

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

(b) one or more processors

(i) processing the multiple images to create a mosaiced image of a region of the retina; and

(ii) controlling movement of visual stimuli presented to a second eye of the human, based on movement of a light source that illuminates the first eye.