Optical coherence tomography apparatus, image processing apparatus, image processing method, and storage medium

Patent metadata

Field	Value
Publication number	US-10849494-B2
Application number	US-201816113820-A
Country	US
Kind code	B2
Filing date	Aug 27, 2018
Priority date	Sep 4, 2017
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

An apparatus includes an interference optical system configured to acquire a tomographic image of an eye by using interference light between return light from the eye irradiated with measurement light and reference light corresponding to the measurement light, a determination unit configured to determine, by using at least one of information about an acquisition time for acquiring the tomographic image and information about an imaging view angle of the tomographic image, a search range for searching for a position corresponding to a first tomographic image of the eye, the position being in a second tomographic image of the eye, and the second tomographic image having been acquired at a time different from a time when the first tomographic image is acquired, and a registration unit configured to perform registration of the first tomographic image and the second tomographic image by using information about the determined search range.

First claim

What is claimed is:

1. An optical coherence tomography apparatus comprising:
an interference optical system configured to acquire a tomographic image of an eye by using interference light between return light from the eye irradiated with measurement light and reference light corresponding to the measurement light;
a determination unit configured to determine, by using information about an acquisition time for acquiring the tomographic image, a search range for searching for a position corresponding to a first tomographic image of the eye, the position being in a second tomographic image of the eye, and the second tomographic image having been acquired at a time different from a time when the first tomographic image is acquired; and
a registration unit configured to perform registration of the first tomographic image and the second tomographic image by using information about the determined search range.

2. The optical coherence tomography apparatus according to claim 1 ,
wherein the information about the acquisition time for acquiring the tomographic image is an acquisition time interval for acquiring a plurality of tomographic images of the eye at different times, and
wherein the determination unit determines the search range in such a manner that the search range increases as the acquisition time interval becomes longer.

3. The optical coherence tomography apparatus according to claim 2 , further comprising a scanning unit configured to scan the eye with the measurement light, wherein the acquisition time interval is an acquisition time for acquiring one tomographic image in a case where the tomographic image is acquired in both a forward path and a backward path for reciprocating scanning by the scanning unit.

4. The optical coherence tomography apparatus according to claim 2 , further comprising a scanning unit configured to scan the eye with the measurement light, wherein in a case where a tomographic image is acquired in a forward path for reciprocating scanning by the scanning unit and no tomographic image is acquired in a backward path for the reciprocating scanning, the acquisition time interval is an acquisition time interval between acquisitions of two successive tomographic images and includes a travel time of the scanning unit from an end of one main scanning operation by the scanning unit to a start of a subsequent main scanning operation.

5. The optical coherence tomography apparatus according to claim 1 , wherein the information about the acquisition time for acquiring the tomographic image indicates the number of pieces of A-scan data on one tomographic image, and the determination unit determines the search range in such a manner that the search range increases as the number of pieces of the A-scan data increases.

6. The optical coherence tomography apparatus according to claim 1 ,
wherein the information about the acquisition time for acquiring the tomographic image indicates either one of a readout rate of a detection unit configured to detect the interference light and a swept source rate of a swept source light source, and
wherein the determination unit determines the search range in such a manner that the search range increases as the rate decreases.

7. The optical coherence tomography apparatus according to claim 1 , further comprising a scanning unit configured to scan the eye with the measurement light, wherein the information about the acquisition time for acquiring the tomographic image indicates a scanning rate and a scanning angle of the scanning unit.

8. The optical coherence tomography apparatus according to claim 1 , wherein the registration unit performs the registration of the first tomographic image and the second tomographic image by correcting, for a plurality of regions elongated in a depth direction of the eye and set in the second tomographic image, a positional deviation between the first tomographic image and the second tomographic image in the depth direction of the eye.

9. The optical coherence tomography apparatus according to claim 1 , further comprising a generation unit configured to generate motion contrast data by using the first tomographic image and the second tomographic image that have been subjected to the registration.

10. The optical coherence tomography apparatus according to claim 9 ,
wherein the registration unit performs the registration of the first tomographic image and the second tomographic image by using information about the determined search range and a decorrelation value between the first tomographic image and the second tomographic image, and
wherein the generation unit generates the motion contrast data by using the decorrelation value used for the registration.

11. The optical coherence tomography apparatus according to claim 1 , wherein the registration unit performs the registration between the first tomographic image and the second tomographic image obtained by controlling the measurement light so that a substantially same position is repeatedly scanned with the measurement light by using information about the determined search range.

12. An image processing method comprising:
acquiring a tomographic image of an eye by using interference light between return light from the eye irradiated with measurement light and reference light corresponding to the measurement light;
determining, by using information about an acquisition time for acquiring the tomographic image, a search range for searching for a position corresponding to a first tomographic image of the eye, the position being in a second tomographic image of the eye, and the second tomographic image having been acquired at a time different from a time when the first tomographic image is acquired; and
performing registration of the first tomographic image and the second tomographic image by using information about the determined search range.

13. A non-transitory computer-readable storage medium storing a program for causing a computer to execute the method according to claim 12 .

Assignees

• Canon Kk

Inventors

• Uchida Hiroki

Classifications

• A61B3/1225

  using coherent radiation · CPC title

• A61B3/102 Primary

  for optical coherence tomography [OCT] · CPC title

• A61B3/0025

  characterised by electronic signal processing, e.g. eye models · CPC title