Hand-held portable fundus camera for screening photography

Patent metadata

Field	Value
Publication number	US-2022071486-A1
Application number	US-202117302123-A
Country	US
Kind code	A1
Filing date	Apr 23, 2021
Priority date	Sep 4, 2009
Publication date	Mar 10, 2022
Grant date	—

Abstract

System and Method pertaining to the modification and integration of an existing consumer digital camera, for example, with an optical imaging module to enable point and shoot fundus photography of the eye. The auto-focus macro capability of existing consumer cameras is adapted to photograph the retina over an extended diopter range, eliminating the need for manual diopter focus adjustment. The thru-the-lens (TTL) auto-exposure flash capability of existing consumer cameras is adapted to photograph the retina with automatic flash exposure eliminating the need for manual flash adjustment. The consumer camera imaging sensor and flash are modified to allow the camera sensor to perform both non-mydriatic focusing of the retina using infrared illumination and standard color flash photography of the retina without the need for additional imaging sensors or mechanical filters. These modifications and integration of existing consumer cameras for fundus photography of the eye significantly improve ease of manufacture and usability.

First claim

1 . An optical system configured for integration with a consumer camera to provide, when mated with the consumer camera, a unitized hand-held assembly for non-mydriatic, automatically focused photography of a fundus of an eye, the optical system comprising:
an infrared composing source, the infrared composing source having an infrared output detectable by an image sensor of the consumer camera to facilitate automatic focusing by the consumer camera when the consumer camera is operated without an infrared blocking filter; a final image acquisition illumination source; a front objective lens; transmission and relay optics configured to:
transmit the infrared output from the infrared composing source and a visible-light output from the final image acquisition illumination source through the front objective lens to illuminate a retina;
receive through the front objective lens a field of view including the retina; and
relay to the image sensor of the consumer camera the received field of view for capture by the consumer camera; and
a control circuit communicatively coupled to the infrared composing source and the final image acquisition illumination source, the control configured to control the infrared composing source and the final image acquisition illumination source in coordination with automatic focusing and image acquisition by the consumer camera.

2 . The optical system of claim 1 , wherein the visible light output by the final image acquisition illumination source comprises white light.

3 . The optical system of claim 1 , comprising an interface to integrate the optical system with the consumer camera electrically and mechanically.

4 . The optical system of claim 3 , wherein the interface is configured to receive a signal from the consumer camera indicative that image acquisition is triggered.

5 . The optical system of claim 3 , wherein the interface is configured to provide a signal to the consumer camera triggering at least one of a focusing operation or an image acquisition.

6 . The optical system of claim 3 , wherein the interface is configured to trigger a shift in focal position corresponding to a difference in focal length between the infrared output and the visible light output.

7 . The optical system of claim 3 , comprising a housing defining a mechanical configuration to mate with the consumer camera.

8 . The optical system of claim 7 , wherein the housing is configured to mate with a lens mount of the consumer camera.

9 . The optical system of claim 3 , wherein the interface comprises at least one of a macro extension or a macro lens.

10 . A method for non-mydriatic, automatically focused photography of a fundus of an eye using a consumer camera and an optical system mated to the consumer camera, the method comprising:
triggering operation of an infrared composing source, the infrared composing source having an infrared output detectable by an image sensor of the consumer camera to facilitate automatic focusing by the consumer camera when the consumer camera is operated without an infrared blocking filter; transmitting the infrared output from the infrared composing source through transmission and relay optics through a front objective lens to illuminate a retina; receiving through the front objective lens a field of view including the retina illuminated by the infrared output; triggering operation of an automatic focusing feature of the consumer camera using the received field of view illuminated by the infrared output; triggering operation of a final image acquisition illumination source; transmitting a visible-light output from the final image acquisition illumination source through the front objective lens to illuminate the retina; and receiving through the front objective lens a field of view including the retina illuminated by the visible light output.

11 . The method of claim 10 , wherein the visible light output by the final image acquisition illumination source comprises white light.

12 . The method of claim 10 , comprising physically mating the optical system to the consumer camera to integrate the optical system with the consumer camera electrically and mechanically.

13 . The method of claim 12 , wherein the physically mating includes engaging a lens mount of the consumer camera using the optical system.

14 . The method of claim 13 , wherein the physically mating includes mating the optical system with a flash shoe of the consumer camera.

15 . The method of claim 10 , comprising, at the optical system, receiving a signal from the consumer camera indicative that image acquisition is triggered; and
in response, triggering the operation of a final image acquisition illumination source.

16 . The method of claim 10 , comprising, at the optical system, generating a signal to the consumer camera triggering at least one of a focusing operation or an image acquisition.

17 . The method of claim 16 , comprising, at the optical system, generating a signal to the consumer camera triggering a shift in focal position corresponding to a difference in focal length between the infrared output and the visible light output.

18 . The method of claim 10 , comprising modifying the consumer camera to remove an infrared blocking filter.

19 . A hand-held portable fundus camera system comprising:
a consumer visible-light camera configured for operation without an infrared blocking filter; an optical system mated with the consumer camera to provide, when mated with the consumer camera, a unitized hand-held assembly for non-mydriatic, automatically focused photography of a fundus of an eye, the optical system comprising:
an infrared composing source, the infrared composing source having an infrared output detectable by an image sensor of the consumer camera to facilitate automatic focusing by the consumer camera when the consumer camera is operated without an infrared blocking filter;
a final image acquisition illumination source;
a front objective lens;
transmission and relay optics configured to:
transmit the infrared output from the infrared composing source and a visible-light output from the final image acquisition illumination source through the front objective lens to illuminate a retina;
receive through the front objective lens a field of view including the retina; and
relay to the image sensor of the consumer camera the received field of view for capture by the consumer camera; and

a control circuit communicatively coupled to the infrared composing source and the final image acquisition illumination source, the control configured to control the infrared composing source and the final image acquisition illumination source in coordination with automatic focusing and image acquisition by the consumer camera.

20 . The hand-held portable fundus camera system of claim 19 , wherein the optical system comprises an interface to integrate the optical system with a corresponding interface of the consumer camera;
wherein the interface is configured to provide a signal to the consumer camera triggering at least one of a focusing operation or an image acquisition and to provide a signal to the consumer camera triggering a focusing operation.

Assignees

• Univ Virginia Patent Foundation

Inventors

• Yates Paul Andrew
• Tran Kenneth

Classifications

• A61B3/12

  for looking at the eye fundus, e.g. ophthalmoscopes (A61B3/13 takes precedence) · CPC title

• A61B3/1208

  Multiple lens hand-held instruments · CPC title

• A61B3/156 Primary

  for blocking · CPC title

• G06V40/19

  Sensors therefor · CPC title

• A61B3/14

  Arrangements specially adapted for eye photography · CPC title