Construction of an individual eye model using a plenoptic camera

• US 9,955,861 B2
• Filed: 03/07/2016
• Issued: 05/01/2018
• Est. Priority Date: 10/16/2015
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Gao, Liang, Tosic, Ivana
• Primary Examiner(s): SAHLE, MAHIDERE S
• Application Number:
  US15/063,254
• Publication Number:
  US 20170105615A1
• Time in Patent Office: 785 Days
• Field of Search: 351206
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/1015 for wavefront analysis
• CPC Class Codes: A61B 3/107 for determining the shape or measuring the curvature of the cornea
• CPC Class Codes: A61B 3/1173 for examining the eye lens
• CPC Class Codes: A61B 3/14 Arrangements specially adapted for eye photography apparatus or arrangements for taking photographs per se G03B
• CPC Class Codes: A61B 3/158 of corneal reflection
• CPC Class Codes: G06T 2207/30041 Eye; Retina; Ophthalmic
• CPC Class Codes: G06T 7/557 from light fields, e.g. from plenoptic cameras

Abstract

A single imaging platform for making in vivo measurements of an individual'"'"'s eye, where the measurements are sufficient to construct an optical model of the individual'"'"'s eye. The platform includes a plenoptic opthalmic camera and an illumination module. In one configuration, the plenoptic opthalmic camera captures a plenoptic image of a corneal anterior surface of the individual'"'"'s eye. In another configuration, the plenoptic opthalmic camera operates as a wavefront sensor to measure a wavefront produced by the individual'"'"'s eye.

Claims

1. A method for constructing an optical model of an individual'"'"'s eye using a plenoptic opthalmic camera, the method comprising:

the plenoptic opthalmic camera capturing in vivo a plenoptic image of a corneal anterior surface of the individual'"'"'s eye;

the plenoptic opthalmic camera operating as a wavefront sensor to measure in vivo a wavefront produced by the individual'"'"'s eye; and

generating the optical model of the individual'"'"'s eye, wherein the optical model of the individual'"'"'s eye includes optical models of the corneal anterior surface of the individual'"'"'s eye, of a lens anterior surface of the individual'"'"'s eye, and of a lens posterior surface of the individual'"'"'s eye; and

generating the optical models comprises;

generating the optical model for the corneal anterior surface of the individual'"'"'s eye based on the captured plenoptic image; and

generating the optical models for the lens anterior surface and for the lens posterior surface of the individual'"'"'s eye based on the measured wavefront and based on the optical model for the corneal anterior surface.

2. The method of claim 1 wherein the optical models of the corneal anterior surface, of the lens anterior surface, and of the lens posterior surface are each expressed using Zernike polynomials.

3. The method of claim 1 wherein the optical models of the corneal anterior surface, of the lens anterior surface, and of the lens posterior surface are each expressed in a format suitable for use with optical design software.

4. The method of claim 1 wherein generating the optical model of the corneal anterior surface of the individual'"'"'s eye comprises:

calculating a disparity map for the captured plenoptic image; and

generating a depth map of the corneal anterior surface based on the disparity map.

5. The method of claim 4 wherein capturing in vivo the plenoptic image of the corneal anterior surface comprises:

illuminating the corneal anterior surface with a predefined pattern; and

the plenoptic opthalmic camera capturing the plenoptic image of the corneal anterior surface as illuminated by the predefined pattern.

6. The method of claim 4 wherein generating a depth map of the corneal anterior surface based on disparity in the captured plenoptic image of the corneal anterior surface comprises:

calibrating a depth-disparity mapping for the plenoptic opthalmic camera; and

generating the depth map of the corneal anterior surface based on the calibrated depth-disparity mapping.

7. The method of claim 1 wherein generating the optical models for the lens anterior surface and for the lens posterior surface of the individual'"'"'s eye based on the measured wavefront and based on the optical model for the corneal anterior surface comprises:

creating a computer simulation of the individual'"'"'s eye, the computer simulation including the generated optical model for the corneal anterior surface, and optical models for the lens anterior surface and for the lens posterior surface;

using the computer simulation to simulate a wavefront produced by the individual'"'"'s eye; and

optimizing the optical models for the lens anterior surface and for the lens posterior surface to reduce a difference between the simulated wavefront and the measured wavefront.

8. The method of claim 1 wherein measuring in vivo the wavefront produced by the individual'"'"'s eye comprises:

illuminating the individual'"'"'s eye to produce a point image on a retina of the individual'"'"'s eye; and

the plenoptic opthalmic camera operating as a wavefront sensor to measure in vivo the wavefront produced by the point image reflected from the retina of the individual'"'"'s eye.

9. A single imaging platform for making in vivo measurements of an individual'"'"'s eye, the measurements sufficient to construct an optical model of the individual'"'"'s eye, the single imaging platform comprising:

an illumination module for illuminating the individual'"'"'s eye; and

a plenoptic opthalmic camera for acquiring measurements of the individual'"'"'s eye illuminated by the illumination module;

wherein the illumination module and the plenoptic opthalmic camera are configurable for;

a first configuration in which the plenoptic opthalmic camera captures in vivo a plenoptic image of a corneal anterior surface of the individual'"'"'s eye; and

a second configuration in which the plenoptic opthalmic camera operates as a wavefront sensor to measure in vivo a wavefront produced by the individual'"'"'s eye; and

a post-processing module that generates the optical model of the individual'"'"'s eye, wherein the optical model of the individual'"'"'s eye includes optical models of the corneal anterior surface of the individual'"'"'s eye, of a lens anterior surface of the individual'"'"'s eye, and of a lens posterior surface of the individual'"'"'s eye; and

generating the optical models comprises;

generating the optical model for the corneal anterior surface of the individual'"'"'s eye based on the captured plenoptic image; and

generating the optical models for the lens anterior surface and for the lens posterior surface of the individual'"'"'s eye based on the measured wavefront and based on the optical model for the corneal anterior surface.

10. The single imaging platform of claim 9 wherein, in the first configuration, the illumination module illuminates the corneal anterior surface with a predefined pattern, and the plenoptic opthalmic camera captures the plenoptic image of the corneal anterior surface as illuminated by the predefined pattern.

11. The single imaging platform of claim 9 wherein, in the second configuration, the illumination module produces a point image on a retina of the individual'"'"'s eye, and the plenoptic opthalmic camera operates as a wavefront sensor to measure in vivo the wavefront produced by the point image reflected from the retina of the individual'"'"'s eye.

12. The single imaging platform of claim 9 further comprising:

a beamsplitter positioned to allow simultaneous illumination of the individual'"'"'s eye by the illumination module and acquisition of measurements by the plenoptic opthalmic camera.

13. The single imaging platform of claim 12 wherein the beamsplitter rejects light that is specularly reflected from the cornea and passes light that is scattered from the cornea.

20. The single imaging platform of claim 9 wherein the optical models of the corneal anterior surface, of the lens anterior surface, and of the lens posterior surface are each expressed in a format suitable for use with optical design software.

14. A non-transitory computer-readable storage medium storing executable computer program instructions for constructing an optical model of an individual'"'"'s eye using measurements captured by a plenoptic opthalmic camera, the instructions executable by a computer system and causing the computer system to perform a method comprising:

accessing a plenoptic image of a corneal anterior surface of the individual'"'"'s eye, the plenoptic image captured in vivo by a plenoptic opthalmic camera;

accessing a measurement of a wavefront produced by the individual'"'"'s eye, the wavefront measured in vivo by the plenoptic opthalmic camera operating as a wavefront sensor; and

generating the optical model of the individual'"'"'s eye based on the captured plenoptic image and the measured wavefront, wherein the optical model of the individual'"'"'s eye includes optical models of the corneal anterior surface of the individual'"'"'s eye, of a lens anterior surface of the individual'"'"'s eye, and of a lens posterior surface of the individual'"'"'s eye; and

generating the optical models comprises;

generating the optical model for the corneal anterior surface of the individual'"'"'s eye based on the captured plenoptic image; and

generating the optical models for the lens anterior surface and for the lens posterior surface of the individual'"'"'s eye based on the measured wavefront and based on the optical model for the corneal anterior surface.

15. The non-transitory computer-readable storage medium of claim 14 wherein the optical models of the corneal anterior surface, of the lens anterior surface, and of the lens posterior surface are each expressed using Zernike polynomials.

16. The non-transitory computer-readable storage medium of claim 14 wherein the optical models of the corneal anterior surface, of the lens anterior surface, and of the lens posterior surface are each expressed in a format suitable for use with optical design software.

17. The non-transitory computer-readable storage medium of claim 14 wherein generating the optical model of the corneal anterior surface of the individual'"'"'s eye comprises:

calculating a disparity map for the captured plenoptic image; and

generating a depth map of the corneal anterior surface based on the disparity map.

18. The non-transitory computer-readable storage medium of claim 17 wherein generating a depth map of the corneal anterior surface based on disparity in the captured plenoptic image of the corneal anterior surface comprises:

calibrating a depth-disparity mapping for the plenoptic opthalmic camera; and

generating the depth map of the corneal anterior surface based on the calibrated depth-disparity mapping.

19. The non-transitory computer-readable storage medium of claim 14 wherein generating the optical models for the lens anterior surface and for the lens posterior surface of the individual'"'"'s eye based on the measured wavefront and based on the optical model for the corneal anterior surface comprises:

creating a computer simulation of the individual'"'"'s eye, the computer simulation including the generated optical model for the corneal anterior surface, and optical models for the lens anterior surface and for the lens posterior surface;

using the computer simulation to simulate a wavefront produced by the individual'"'"'s eye; and

optimizing the optical models for the lens anterior surface and for the lens posterior surface to reduce a difference between the simulated wavefront and the measured wavefront.