Optical coherence tomography method, system and computer program product therefor

Patent metadata

Field	Value
Publication number	US-10743759-B2
Application number	US-201615559266-A
Country	US
Kind code	B2
Filing date	Mar 17, 2016
Priority date	Mar 19, 2015
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

The present invention relates to an optical coherence tomography method, comprising: providing a beam of imaging radiation from a radiation source of an optical coherence tomography apparatus; directing, using directing optics, the beam of imaging radiation towards a fundus of a human or animal eye; and receiving a reflected portion of the imaging radiation by the optical coherence tomography apparatus; wherein the method further comprises: providing, by a tracking camera, a tracking image of an image area covering at least a part of said fundus; analyzing the tracking image for detecting a displacement of the fundus; and adapting, at least dependent on the detected displacement, a direction of the beam of imaging radiation by actuating an optical correction unit of said direction optics; and in addition to said adapting of the direction of the beam of imaging radiation, adapting a location of the image area on said fundus imaged by the tracking camera at least dependent on the detected displacement.

First claim

The invention claimed is:

1. Optical retinal imaging method, comprising:
providing a beam of imaging radiation from a radiation source of an optical retinal imaging apparatus; directing, using directing optics, the beam of imaging radiation towards a fundus of a human or animal eye; and receiving a reflected portion of the imaging radiation by the optical retinal imaging apparatus;
wherein the method further comprises:
providing, by a tracking camera, a plurality of subsequent tracking images wherein each of the tracking images is obtained by the tracking camera at once within an exposure time, the tracking images including an image area covering at least a part of said fundus;
analyzing each of the tracking images by comparing with one or more earlier images for detecting a displacement of the fundus; and
adapting, at least dependent on the detected displacement, a direction of the beam of imaging radiation by actuating an optical corrector of said direction optics; and
in addition to said adapting of the direction of the beam of imaging radiation, adapting a location of the image area on said fundus imaged by the tracking camera at least dependent on the detected displacement.

2. Optical retinal imaging method according to claim 1 , wherein said adapting of the location of the image area on the fundus is achieved by disposing the tracking camera such as to receive an optical tracking signal of said image area by the tracking camera via the optical corrector.

3. Optical retinal imaging method according to claim 1 , further including a step of providing a reference tracking image, wherein the reference tracking image is obtained using an exposure time longer than an exposure time used for the subsequent tracking images.

4. Optical retinal imaging method according to claim 3 , wherein said step of providing a reference tracking image is performed either by:
obtaining the reference tracking image as a separate step performed prior to the steps of subsequently providing the subsequent tracking images; or
obtaining the reference tracking image by combining image data from two or more of said subsequent tracking images such as to establish the longer exposure time of the reference tracking image.

5. Optical retinal imaging method according to claim 1 , wherein the tracking camera is a fundus camera.

6. Optical retinal imaging method according to claim 1 , wherein the optical retinal imaging method is at least one of a group comprising: an optical coherence tomography method, a confocal scanning laser ophthalmoscopy method, or a line scanning laser ophthalmoscopy method.

7. Optical retinal imaging method according to claim 1 , wherein said adapting of the location of the image area on the fundus is achieved by disposing the tracking camera such as to receive an optical tracking signal of said image area by the tracking camera via the optical corrector, further including a step of providing a reference tracking image, wherein the reference tracking image is obtained using an exposure time longer than an exposure time used for the subsequent tracking images.

8. Optical retinal imaging method according to claim 7 , wherein said step of providing a reference tracking image is performed either by:
obtaining the reference tracking image as a separate step performed prior to the steps of subsequently providing the subsequent tracking images; or
obtaining the reference tracking image by combining image data from two or more of said subsequent tracking images such as to establish the longer exposure time of the reference tracking image.

9. Optical retinal imaging system, comprising
an optical retinal imaging apparatus including a radiation source for providing a beam of imaging radiation, an optical receiver for receiving a reflected portion of the imaging radiation, and an analyzer for analyzing the received reflected portion of the imaging radiation;
the optical retinal imaging system further comprising
directing optics for directing the beam of imaging radiation towards a fundus of a human or animal eye, a tracking camera for providing a plurality of subsequent tracking images wherein each tracking image is obtained by the tracking camera at once within an exposure time, the tracking images including an image area covering at least a part of said fundus, and a controller for receiving the tracking images and analyzing each tracking image by comparing with one or more earlier images for detecting a displacement of the fundus during irradiation thereof by the optical retinal imaging apparatus;
wherein the directing optics include:
an optical corrector operatively connected to the controller for enabling adapting of a direction of the beam of imaging radiation at least dependent on the detected displacement, by actuation of the optical corrector; and
a camera image corrector for adapting, in addition to said adapting of the direction of the beam of imaging radiation, a location of the image area on said fundus imaged by the tracking camera at least dependent on the detected displacement.

10. Optical retinal imaging system according to claim 9 , wherein the camera image corrector comprises the optical corrector.

11. Optical retinal imaging system according to claim 9 , wherein the tracking camera is a fundus camera.

12. Optical retinal imaging system according to claim 9 , wherein the optical corrector comprises at least one mirror connected to an actuator for controlling at least one of the orientation or position of the mirror relative to the beam of imaging radiation for adapting the direction thereof.

13. Optical retinal imaging system according to claim 9 , further comprising a scanner for enabling scanning of said beam of imaging radiation across the fundus.

14. Optical retinal imaging system according to claim 9 , wherein the controller is further arranged for obtaining a reference tracking image, wherein the reference tracking image is obtained using an exposure time and/or illumination power larger than that used for the subsequent tracking images.

15. Optical retinal imaging system according to claim 14 , wherein the controller is arranged for obtaining the reference tracking image by combining image data from two or more of said subsequent tracking images such as to establish the longer exposure time of the reference tracking image.

16. Optical retinal imaging system according to claim 9 , wherein the optical retinal imaging system comprises at least one of a group comprising: an optical coherence tomography system, a confocal scanning laser ophthalmoscopy system, or a line scanning laser ophthalmoscopy system.

17. Optical retinal imaging system according to claim 9 , wherein the tracking camera is disposed such as to receive an optical tracking signal of said image area by the tracking camera via the optical corrector.

18. Optical retinal imaging system according to claim 17 , wherein the controller is arranged for receiving a plurality of subsequent tracking images during said providing of the beam of imaging radiation, wherein the controller is further arranged for obtaining a reference tracking image, wherein the reference tracking image is obtained using an exposure time and/or illumination power larger than that used for the subsequent tracking images.

19. Optical retinal imaging system according to claim 18 , wherein the controller is arranged for obtaining the reference tracking image by combining image data from two or more of said subsequent tracking images such as to establish the longer exposure time of the reference track

Assignees

• Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno

Inventors

• Kuiper Stefan
• Doelman Nicolaas Jan
• Liebig Thomas
• Klop Willem Arjan

Classifications

• A61B3/15

  with means for aligning, spacing or blocking spurious reflection {; with means for relaxing} · CPC title

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title

• G01B9/02091

  Tomographic interferometers, e.g. based on optical coherence · CPC title

• A61B3/1225

  using coherent radiation · CPC title

• A61B3/102 Primary

  for optical coherence tomography [OCT] · CPC title