Active visual alignment stimuli in fundus photography

Patent metadata

Field	Value
Publication number	US-11844573-B2
Application number	US-202117321672-A
Country	US
Kind code	B2
Filing date	May 17, 2021
Priority date	Oct 30, 2017
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

The technology described herein is directed to a fundus camera and, more specifically, to a fundus camera having a display that projects active visual alignment stimuli onto an eye of an examinee via one or more components of an optimal assembly. The active visual alignment stimuli are dynamically adjusted to guide an examinee toward optical alignment for fundus imaging.

First claim

The invention claimed is:

1. A method of operating a fundus camera comprising:
projecting an animated fixation target onto an eye of an examinee via an optical assembly, wherein the animated fixation target comprises a continuously moving animation;
emitting one or more flashes onto the eye of the examinee via the optical assembly;
capturing, with the fundus camera, one or more images of the examinee's fundus during the one or more flashes; and
dynamically adjusting the animated fixation target within a fixation zone for facilitating dilation of a pupil of the eye while guiding the examinee's line of sight toward fixation alignment.

2. The method of claim 1 , wherein dynamically adjusting the animated fixation target within the fixation zone comprises progressively shrinking the animated fixation target until the animated fixation target becomes a fixation point.

3. The method of claim 1 , wherein dynamically adjusting the animated fixation target within the fixation zone comprises progressively shrinking the fixation zone until the fixation zone becomes a fixation point, and wherein progressively shrinking the fixation zone comprises maintaining a relative position of the animated fixation target within the fixation zone.

4. The method of claim 1 , wherein multiple images are captured during one flash.

5. The method of claim 1 , wherein each of the one or more images captured correspond to one of the one or more flashes.

6. The method of claim 1 , further comprising:
monitoring, with an eye tracker, the eye of the examinee while dynamically adjusting, based on an output of the eye tracker, the animated fixation target within the fixation zone.

7. The method of claim 6 , wherein the eye tracker tracks a location or size of the examinee's pupil, and wherein dynamically adjusting the animated fixation target is based on the location or size of the examinee's pupil.

8. The method of claim 6 , further comprising:
determining that the fixation alignment is achieved based on the output of the eye tracker; and
triggering, responsive to the determination that the fixation alignment is achieved, an illumination source to emit the one or more flashes and the fundus camera to capture the one or more images of the examinee's fundus.

9. The method of claim 6 , wherein the output of the eye tracker comprises a real-time video feed, the method further comprising:
projecting the real-time video feed onto the eye of the examinee.

10. The method of claim 1 , further comprising:
monitoring a time of adaptation of the eye of the examinee; and
increasing an illumination of the fixation target if the time of adaptation is above a threshold.

11. The method of claim 1 , further comprising:
monitoring a size of a pupil of the eye of the examinee; and
in response to determining that the pupil has stopped growing and before dark adaptation commences, triggering an illumination source to emit the one or more flashes and the fundus camera to capture the one or more images of the examinee's fundus.

12. The method of claim 1 , further comprising:
monitoring a size of a pupil of the eye of the examinee; and
in response to determining that the size of the pupil exceeds a threshold value, triggering an illumination source to emit the one or more flashes and the fundus camera to capture the one or more images of the examinee's fundus.

13. A fundus camera comprising:
a display adapted to project an animated fixation target onto an eye of an examinee via an optical assembly, wherein the animated fixation target comprises a continuously moving animation;
a camera adapted to capture one or more images of the examinee's fundus; and
a control system operably coupled with the display and the camera and configured to direct the display to dynamically adjust the animated fixation target within a fixation zone for facilitating dilation of a pupil of the eye while guiding the examinee's line of sight toward fixation alignment.

14. The fundus camera of claim 13 , wherein to dynamically adjust the animated fixation target within the fixation zone, the control system is configured to direct the display to progressively shrink the animated fixation target until the animated fixation target becomes a fixation point.

15. The fundus camera of claim 13 , wherein the control system is further configured to monitor a time of adaptation of the eye of the examinee and increase an illumination of the fixation target if the time of adaptation is above a threshold.

16. The fundus camera of claim 13 , further comprising:
an eye tracker, operably coupled with the control system and adapted to track a size of a pupil of the eye of the examinee, and wherein the control system is further configured to trigger, responsive to a determination that the size of the pupil has stopped growing and before dark adaptation commences, the camera to capture the one or more images of the examinee's fundus.

17. The fundus camera of claim 13 , further comprising:
an eye tracker, operably coupled with the control system and adapted to track a size of a pupil of the eye of the examinee, and wherein the control system is further configured to trigger, responsive to a determination that the size of the pupil exceeds a threshold value, the camera to capture the one or more images of the examinee's fundus.

18. The fundus camera of claim 13 , wherein multiple images are captured during one flash.

19. The fundus camera of claim 13 , further comprising:
an eye tracker adapted to monitor the eye of the examinee, the eye tracker comprising an iris camera and an infrared illumination source positioned to illuminate the eye of the examinee wherein the control system directs the display to dynamically adjust, based on an output of the eye tracker, the animated fixation target within the fixation zone.

20. The fundus camera of claim 13 , wherein each of the one or more images captured correspond to one of the one or more flashes.

Assignees

• Verily Life Sciences Llc

Inventors

• Kramer Ryan
• Kavusi Sam
• Glik Eliezer
• Lee Seung Ah
• Belthangady Chinmay

Classifications

• A61B3/152 Primary

  for aligning · CPC title

• A61B3/0041 Primary

  characterised by display arrangements · CPC title

• A61B3/0091 Primary

  Fixation targets for viewing direction · CPC title

• A61B3/032

  Devices for presenting test symbols or characters, e.g. test chart projectors (A61B3/036 takes precedence) · CPC title

• A61B3/112

  for measuring diameter of pupils · CPC title