Method of motion correction in optical coherence tomography imaging

Patent metadata

Field	Value
Publication number	US-9706915-B2
Application number	US-201514861589-A
Country	US
Kind code	B2
Filing date	Sep 22, 2015
Priority date	Jan 21, 2005
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. Significant sample motion may occur during acquisition of the second set. A-scans from the first set are matched with A-scans from the second set, based on similarity between the longitudinal optical scattering profiles they contain. Such matched pairs of A-scans are likely to correspond to the same region in the sample. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair, in conjunction with any shift in the longitudinal scattering profiles between the pair of A-scans, reveals the displacement of the sample between acquisition of the first and second A-scans in the pair. Estimates of the sample displacement are used to correct the transverse and longitudinal coordinates of the A-scans in the second set, to form a motion-corrected OCT data set.

First claim

What is claimed is:

1. A method for collecting optical coherence tomography (OCT) image data of a region of a sample, said method comprising:
acquiring a first set of A-scans over the region of the sample by scanning light over a plurality of locations in the region, said first set being acquired quickly enough that the sample is substantially stationary during the acquisition;
acquiring a second set of A-scans over the region of the sample by scanning light over a plurality of locations in the region;
while acquiring the second set of A-scans, comparing A-scans in the first and second sets to identify A-scans taken at the same locations within the region;
using the identified A-scans to calculate a displacement of the sample; and
adjusting the scanning location for subsequent A-scans based on the calculated displacement.

2. A method as recited in claim 1 , wherein the sample is an eye.

3. A method as recited in claim 1 , wherein the A-scans in the first and second sets are taken at different spacings over the region.

4. A method as recited in claim 1 , wherein the comparison involves cross-correlations.

5. A method as recited in claim 1 , wherein the scanning is performed in a raster pattern.

6. A method as recited in claim 1 , wherein the scanning is performed in a radial or circular pattern.

7. A method as recited in claim 1 , wherein the displacement is a transverse displacement.

8. A method as recited in claim 1 , wherein the displacement is a longitudinal displacement.

9. A method as recited in claim 1 , wherein the first set of A-scans is collected in less than 200 ms.

10. A method as recited in claim 1 , wherein the first set of A-scans is collected in less than 100 ms.

11. An optical coherence tomography (OCT) device for imaging a region of a sample comprising:
a light source for generating a beam of radiation;
a beam divider for directing a first portion of the light into a reference arm and a second portion of the light into a sample arm;
optics for scanning the beam in the sample arm over a plurality of locations in the region of the sample;
a detector for measuring light radiation returning from the sample and reference arms and generating output signals in response thereto; and
a processor for converting the output signals into three dimensional image information;
said processor for controlling the scanning optics in a manner to acquire a first set of A-scans at a plurality of locations in the region, said first set being acquired quickly enough that the sample is substantially stationary during the acquisition;
said processor for controlling the scanning optics in a manner to acquire a second set of A-scans at a plurality of locations in the region;
while acquiring the second set of A-scans, comparing A-scans in the first and second sets to identify A-scans taken at the same locations within the region;
said processor calculating a displacement of the sample based on the comparison;
said processor adjusting the coordinates of the scanning optics for subsequent A-scans based on the calculated displacement.

12. A device as recited in claim 11 wherein the sample is an eye.

13. A device as recited in claim 11 , wherein the A-scans in the first and second sets are taken at different spacings over the region.

14. A device as recited in claim 11 , wherein the comparison involves cross-correlations.

15. A device as recited in claim 11 , wherein the scanning is performed in a raster pattern.

16. A device as recited in claim 11 , wherein the scanning is performed in a radial or circular pattern.

17. A device as recited in claim 11 , wherein the displacement is a transverse displacement.

18. A device as recited in claim 11 , wherein the displacement is a longitudinal displacement.

19. A device as recited in claim 11 , wherein the first set of A-scans is collected in less than 200 ms.

20. A device as recited in claim 11 , wherein the first set of A-scans is collected in less than 100 ms.

Assignees

• Zeiss Carl Meditec Inc

Inventors

• Everett Matthew J
• O'Hara Keith E

Classifications

• G01B9/02091

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

• A61B3/102 Primary

  for optical coherence tomography [OCT] · CPC title

• G01B9/02077

  of the object · CPC title

• A61B5/0066

  Optical coherence imaging · CPC title

• G01N2021/1787

  Tomographic, i.e. computerised reconstruction from projective measurements · CPC title