System and method for generating a wide-field OCT image of a portion of a sample

• US 9,677,869 B2
• Filed: 12/05/2013
• Issued: 06/13/2017
• Est. Priority Date: 12/05/2012
• Status: Active Grant

• Current Assignee: Perimeter Medical Imaging, Inc. (Perimeter Medical Imaging AI, Inc.)
• Original Assignee: Perimeter Medical Imaging, Inc. (Perimeter Medical Imaging AI, Inc.)
• Inventors: Berkeley, Andrew, Rempel, David, Silver, Jason
• Primary Examiner(s): Lapage, Michael P
• Application Number:
  US14/649,697
• Publication Number:
  US 20160040976A1
• Time in Patent Office: 1,286 Days
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/102 for optical coherence tomography [OCT]
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: G01B 9/02041 characterised by particular imaging or detection techniques
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence
• CPC Class Codes: G01N 21/01 Arrangements or apparatus for facilitating the optical investigation
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B

Abstract

Various embodiments of systems and methods are described herein for obtaining wide field OCT images and other types of image data from at least one portion of a sample. Various embodiments of systems, and methods are described herein for assessing a degree of differentiation for a second region of an OCT image of a tissue sample with respect to another first. Various embodiments of a sample container are also described herein for containing a tissue sample and maintaining the tissue sample in a defined orientation during imaging or handling.

Claims

1. A method for generating a wide field optical coherence tomography (OCT) image of a portion of a sample, wherein the method comprises:

creating a surface map of the sample;

acquiring raw OCT data of the portion of the sample based on the surface map by identifying an initial scan position and a final scan position on the surface map, the initial scan position corresponding to a highest point of the surface of the portion of the sample and the final scan position corresponding to a lowest point of the surface of the portion of the sample, and for a given set of vertical OCT images, acquiring the raw OCT data to generate at least a first OCT image with an upper edge of an imaging window aligned with the initial scan position and a second OCT image with an upper edge of an imaging window aligned with the final scan position;

generating a plurality of OCT images from the raw OCT data; and

combining two or more OCT images of the plurality of OCT images to create the wide field OCT image.

2. The method of claim 1, wherein acquiring the raw OCT data further comprises:

operating a scanning head to capture the raw OCT data; and

adjusting a position of the scanning head with respect to a surface of the sample based on at least one of the surface map and OCT imaging parameters for the wide field OCT image.

3. The method of claim 2, further comprising adjusting the position of the scanning head from a first position to a second position that is different from the first position to accommodate unevenness at a surface of the portion of the sample.

4. The method of claim 1, wherein the focus used to acquire the raw OCT data used to generate the OCT images is substantially constant.

5. The method of claim 1, wherein the method further comprises detecting a surface position for each OCT image.

6. The method of claim 5, wherein detecting the surface position for a given OCT image comprises:

identifying a signal portion associated with the given OCT image having a highest intensity value; and

associating a depth position corresponding to the signal portion having the highest intensity value as the surface position.

7. The method of claim 1, wherein combining two or more OCT images comprises:

aligning the first OCT image with a neighbouring OCT image; and

overlaying a portion of the first OCT image over a portion of the neighbouring OCT image to create a composite OCT image.

8. The method of claim 7, wherein at least one of the first OCT image and the neighbouring OCT image is a composite OCT image resulting from the combination of at least two other OCT images.

9. The method of claim 7, wherein the neighbouring OCT image corresponds to a first section of a surface of the sample and the first OCT image corresponds to a second section of the surface of the sample that is different from the first section.

10. The method of claim 9, wherein the second section and the first section are from a horizontal image set obtained from the sample.

11. The method of claim 7, wherein the neighbouring OCT image and the first OCT image correspond to the same section of a surface of the sample and different depth positions of the sample.

12. The method of claim 7, wherein combining two or more OCT images further comprises:

creating a plurality of intermediary composite images by overlaying a portion of the first OCT image over a portion of the neighbouring image, wherein each intermediary composite image includes a different amount of overlap between the OCT image and the neighbouring image;

determining an entropy associated with each intermediary composite image; and

selecting the intermediary composite image associated with a lowest entropy value as the composite OCT image for the first OCT image and the neighbouring OCT image and recording the amount of overlap associated with the selected intermediary composite image.

13. The method of claim 12, wherein combining two or more OCT images further comprises:

identifying a focused portion in each of the first OCT image and the neighbouring OCT image based on the respective surface positions;

overlaying the first OCT image and the neighbouring OCT image based on the recorded amount of overlap; and

retaining, in the composite OCT image, only the focused portions from each of the first OCT image and the neighbouring OCT image.

14. The method of claim 1, wherein acquiring the raw OCT data further comprises minimizing saturation effects in at least one OCT image of the plurality of OCT images by:

detecting a noise signal at a region proximate to an external surface of the sample in the at least one OCT image;

determining whether an intensity of the noise signal exceeds an intensity threshold; and

adjusting characteristics of the at least one OCT image to reduce the intensity of the noise signal when the intensity of the noise signal exceeds the intensity threshold.

15. A system for generating a wide field optical coherence tomography (OCT) image of a portion of a sample, wherein the system comprises:

an input port for receiving raw OCT data;

an image processing module being configured to process the raw OCT data to generate wide field OCT images by creating a surface map of the sample;

acquiring raw OCT data of the portion of the sample based on the surface map by identifying an initial scan position and a final scan position on the surface map, the initial scan position corresponding to a highest point of the surface of the portion of the sample and the final scan position corresponding to a lowest point of the surface of the portion of the sample, and for a given set of vertical OCT images, acquiring the raw OCT data to generate at least a first OCT image with an upper edge of an imaging window aligned with the initial scan position and a second OCT image with an upper edge of an imaging window aligned with the final scan position;

generating a plurality of OCT images from the raw OCT data; and

combining two or more OCT images of the plurality of OCT images to create the wide field OCT image; and

an output port to provide the wide-field OCT images to one of a user, a storage device and another computing device.

16. The system of claim 15, wherein the image processing module is configured to acquire the raw OCT data by:

operating a scanning head to capture the raw OCT data;

adjusting a position of the scanning head with respect to a surface of the sample based on at least one of the surface map and OCT imaging parameters for the wide field OCT image; and

adjusting the position of the scanning head from a first position to a second position that is different from the first position to accommodate unevenness at a surface of the portion of the sample.

17. The system of claim 15, wherein the image processing module is configured to maintain a substantially constant focus to acquire the raw OCT data used to generate the OCT images.

18. The system of claim 15, wherein the image processing module is configured to detect a surface position for each OCT image by:

identifying a signal portion associated with the given OCT image having a highest intensity value; and

associating a depth position corresponding to the signal portion having the highest intensity value as the surface position.

19. The system of claim 15, wherein the image processing module is configured to combine two or more OCT images by:

aligning the first OCT image with a neighbouring OCT image; and

overlaying a portion of the first OCT image over a portion of the neighbouring OCT image to create a composite OCT image.

20. The system of claim 19, wherein at least one of the first OCT image and the neighbouring OCT image is a composite OCT image resulting from the combination of at least two other OCT images.

21. The system of claim 19, wherein the neighbouring OCT image corresponds to a first section of a surface of the sample and the first OCT image corresponds to a second section of the surface of the sample that is different from the first section, and wherein the second section and the first section are from a horizontal image set obtained from the sample.

22. The system of claim 19, wherein the neighbouring OCT image and the first OCT image correspond to the same section of a surface of the sample and different depth positions of the sample.

23. The system of claim 19, wherein the image processing module is configured to combine two or more OCT images further by:

creating a plurality of intermediary composite images by overlaying a portion of the first OCT image over a portion of the neighbouring image, wherein each intermediary composite image includes a different amount of overlap between the OCT image and the neighbouring image;

determining an entropy associated with each intermediary composite image; and

selecting the intermediary composite image associated with a lowest entropy value as the composite OCT image for the first OCT image and the neighbouring OCT image and recording the amount of overlap associated with the selected intermediary composite image.

24. The system of claim 23, wherein the image processing module is further configured to combine the two or more OCT images by:

identifying a focused portion in each of the first OCT image and the neighbouring OCT image based on the respective surface positions;

overlaying the first OCT image and the neighbouring OCT image based on the recorded amount of overlap; and

retaining, in the composite OCT image, only the focused portions from each of the first OCT image and the neighbouring OCT image.

25. The system of claim 15, wherein the image processing module is configured to acquire the raw OCT data further by minimizing saturation effects in at least one OCT image of the plurality of OCT images by:

detecting a noise signal at a region proximate to an external surface of the sample in the at least one OCT image;

determining whether an intensity of the noise signal exceeds an intensity threshold; and

adjusting characteristics of the at least one OCT image to reduce the intensity of the noise signal when the intensity of the noise signal exceeds the intensity threshold.

26. A non-transitory computer-readable medium storing computer-executable instructions, the instructions for causing an image processing module to perform a method for generating a wide field optical coherence tomography (OCT) image of a portion of a sample, wherein the method comprises:

creating a surface map of the sample;

acquiring raw OCT data of the portion of the sample based on the surface map by identifying an initial scan position and a final scan position on the surface map, the initial scan position corresponding to a highest point of the surface of the portion of the sample and the final scan position corresponding to a lowest point of the surface of the portion of the sample and for a given set of vertical OCT images, acquiring the raw OCT data to generate at least a first OCT image with an upper edge of an imaging window aligned with the initial scan position and a second OCT image with an upper edge of an imaging window aligned with the final scan position;

generating a plurality of OCT images from the raw OCT data; and

combining two or more OCT images of the plurality of OCT images to create the wide field OCT image.

27. A method for generating a wide field optical coherence tomography (OCT) image of a portion of a sample, wherein the method comprises:

receiving a set of OCT images corresponding to the portion of the sample, the set of OCT images including a first OCT image and a neighbouring OCT image;

aligning the first OCT image with the neighbouring OCT image; and

overlaying a portion of the first OCT image over a portion of the neighbouring OCT image to create the wide field OCT image by (1) creating a plurality of intermediary composite images based on the first OCT image and the neighbouring image, each intermediary composite image having a different amount of overlap between the OCT image and the neighbouring image, (2) determining an entropy associated with the overlap in each intermediary composite image; and

(3) selecting the intermediary composite image associated with a lowest entropy value as the wide field OCT image for the first OCT image and the neighbouring OCT image and recording the overlap.

28. The method of claim 27, wherein the neighbouring OCT image corresponds to a first section of a surface of the sample and the first OCT image corresponds to a second section of the surface of the sample that is different from the first section, the second section and the first section are from a horizontal image set obtained from the sample and the method comprises using horizontal stitching to create the wide field OCT image.

29. The method of claim 27, wherein the neighbouring OCT image and the first OCT image correspond to the same section of a surface of the sample and different depth positions of the sample and the method comprises using vertical stitching to create the wide field OCT image.

30. The method of claim 27, wherein overlaying the portion of the first OCT image over the portion of the neighbouring OCT image further comprises:

identifying a focused portion in each of the first OCT image and the neighbouring OCT image based on respective surface positions;

overlaying the first OCT image and the neighbouring OCT image based on the recorded overlap to generate the wide field OCT image; and

retaining, in the wide field OCT image, only the focused portions from each of the first OCT image and the neighbouring OCT image.

31. A method for generating a wide field optical coherence tomography (OCT) image of a portion of a sample, wherein the method comprises:

creating a surface map of the sample;

acquiring raw OCT data of the portion of the sample based on the surface map;

generating a plurality of OCT images from the raw OCT data;

combining two or more OCT images of the plurality of OCT images to create the wide field OCT image by;

aligning a first OCT image with a neighbouring OCT image;

creating a plurality of intermediary composite images by overlaying a portion of the first OCT image over a portion of the neighbouring image, wherein each intermediary composite image includes a different amount of overlap between the OCT image and the neighbouring image;

determining an entropy associated with each intermediary composite image; and

selecting the intermediary composite image associated with a lowest entropy value as the composite OCT image for the first OCT image and the neighbouring OCT image and recording the amount of overlap associated with the selected intermediary composite image.

32. A system for generating a wide field optical coherence tomography (OCT) image of a portion of a sample, wherein the system comprises:

an input port for receiving raw OCT data;

an image processing module being configured to process the raw OCT data to generate wide field OCT images by creating a surface map of the sample;

acquire raw OCT data of the portion of the sample based on the surface map;

generate a plurality of OCT images from the raw OCT data; and

combine two or more OCT images of the plurality of OCT images to create the wide field OCT image by;

aligning the first OCT image with a neighbouring OCT image;

overlaying a portion of the first OCT image over a portion of the neighbouring OCT image to create a composite OCT image;

creating a plurality of intermediary composite images by overlaying a portion of the first OCT image over a portion of the neighbouring image, wherein each intermediary composite image includes a different amount of overlap between the OCT image and the neighbouring image;

determining an entropy associated with each intermediary composite image; and

selecting the intermediary composite image associated with a lowest entropy value as the composite OCT image for the first OCT image and the neighbouring OCT image and recording the amount of overlap associated with the selected intermediary composite image; and

an output port to provide the wide-field OCT images to one of a user, a storage device and another computing device.