Method and system for imaging a cell sample

Patent metadata

Field	Value
Publication number	US-10176565-B2
Application number	US-201414285672-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	May 23, 2013
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

The present disclosure provides a method of determining a reference depth level within a cell sample. The method comprises obtaining data representative of a series of images captured by performing a depth scan of the cell sample using a digital microscope, the series of images being associated with a series of depth levels of the cell sample; processing said data for detecting at least one depth level corresponding to a drop in image contrast; and identifying the detected depth level as the reference depth level.

First claim

The invention claimed is:

1. A method for use with a cell sample, the method comprising:
obtaining data representative of a series of images captured by performing a depth scan of the cell sample using a microscope, the series of images being associated with a series of depth levels of the cell sample;
identifying one of the depth levels as being an optimum focal plane for imaging one or more entities within the sample using the microscope, by:
detecting a plurality of depth levels as corresponding to drops in image contrast;
identifying one of the plurality of detected depth levels as corresponding to a deepest drop in image contrast; and
identifying the depth level that corresponds to the deepest drop in image contrast as the depth level that is the optimum focal plane;
and

imaging the cell sample using the microscope, by focusing the microscope at an investigative depth level that is based on the identified depth level.

2. The method according to claim 1 , wherein identifying one of the depth levels as the optimum focal plane comprises identifying that the identified depth level is such that image contrast at the identified depth level is lower than image contrast associated with a depth level immediately preceding the identified depth level in the series of depth levels and lower than image contrast associated with a depth level immediately following the identified depth level in the series of depth levels.

3. The method according to claim 1 , further comprising obtaining data representative of an additional series of images associated with an additional series of depth levels, wherein a scanning depth interval of the additional series of images is wider than a scanning depth interval of the series of images.

4. The method of claim 3 , wherein the obtaining of the data representative of the additional series of images is performed in response to the deepness of the drop in image contrast at the identified depth level being below a predetermined deepness threshold.

5. The method according to claim 1 , wherein detecting the plurality of depth levels as corresponding to drops in image contrast comprises computing, for each image, a contrast related value that enables derivation of an image contrast for each image.

6. The method according to claim 1 , wherein detecting the plurality of depth levels as corresponding to drops in image contrast comprises calculating image contrast as a function of depth level using a contrast function that increases with image contrast, and detecting one or more wells in a contrast curve representing the image contrast as the function of depth level.

7. The method according to claim 6 , wherein identifying one of the depth levels as corresponding to the deepest drop in image contrast comprises detecting that the depth level corresponds to a bottom of one of the wells in the contrast curve.

8. The method according to claim 6 , wherein identifying one of the depth levels as corresponding to the deepest drop in image contrast comprises determining a deepness of the well corresponding to that depth level by:
determining right and left boundary depth levels at which the contrast function becomes inferior to the well bottom contrast;
determining right and left highest contrast values reached by the contrast function between the well bottom depth level and respectively the right and left boundary depth levels; and
calculating a minimum of:
a difference between the right highest contrast value and the well bottom contrast; and
a difference between the left highest contrast value and the well bottom contrast.

9. The method according to claim 1 , wherein detecting the plurality of depth levels as corresponding to drops in image contrast comprises calculating image contrast as a function of depth level using a contrast function that decreases with image contrast and detecting one or more roofs of a contrast curve representing the image contrast as the function of depth level.

10. The method according to claim 9 , wherein identifying one of the depth levels as corresponding to the deepest in image contrast comprises detecting that the depth level corresponds to a top of one of the roofs of the contrast curve.

11. The method according to claim 9 , wherein identifying one of the depth levels as corresponding to the deepest drop in image contrast comprises determining a deepness of the roof corresponding to that depth level by:
determining right and left boundary depth levels at which the contrast function becomes superior to the rooftop contrast;
determining right and left lowest contrast values reached by the contrast function between the roof top depth level and respectively the right and left boundary depth levels; and
calculating a minimum of:
a difference between the roof top contrast and the right lowest contrast value, and
a difference between the roof top contrast and the left lowest contrast value.

12. The method according to claim 1 ,
wherein detecting that the plurality of depth levels as corresponding to drops in image contrast comprises:
calculating image contrast as a function of depth level,
generating a contrast curve representing the image contrast as the function of depth level, and
obtaining one or more supplemental depths levels associated to supplemental contrast values by interpolating or extrapolating the contrast curve; and

wherein identifying the depth level that is at the optimal focal plane comprises identifying, as the depth level that is at the optimum focal plane, one of the one or more supplemental depth levels.

13. The method according to claim 1 , wherein obtaining data representative of the series of images comprises scanning a scanning depth interval of the cell sample using the microscope.

14. The method according to claim 1 , wherein the series of images are associated with a first scanning depth and a second scanning depth that are endpoints of the series of depth levels and the method further comprises verifying at least one of: a first distance between the optimum focal plane and the first scanning depth being above a first predetermined threshold, and a second distance between the optimum focal plane and the second scanning depth being above a second predetermined threshold.

15. The method according to claim 1 , wherein obtaining the data representative of the series of images comprises obtaining data representative of a series of images captured by performing a depth scan of the cell sample using the microscope, the series of images being associated with a series of depth levels of the cell sample, a span of the series of depth levels being 5 to 1000 micrometers.

16. The method according to claim 1 , wherein obtaining the data representative of the series of images comprises obtaining data representative of a series of images captured by performing a depth scan of the cell sample using the microscope, the series of images being associated with a series of depth levels of the cell sample, a span of the series of depth levels being less than 50 micrometers.

17. The method according to claim 1 , further comprising determining an estimated optimum focal plane and wherein obtaining the data representative of the series of images comprises obtaining data representative of a series of images captured by performing a depth scan of the cell sample using the microscope, the series of images being associated with a series of depth levels that covers the estimated optimum focal plane.

18. The method according to claim 1 , wherein focusing the microscope at the investigative depth level f

Assignees

• S D Sight Diagnostics Ltd

Inventors

• Greenfield Yuval
• Bilu Yonatan
• Pollak Joseph Joel
• Yorav-Raphael Noam

Classifications

• G02B21/244

  using image analysis techniques · CPC title

• G02B7/38

  measured at different points on the optical axis {, e.g. focussing on two or more planes and comparing image data} · CPC title

• G06T7/507

  from shading (G06T7/586 takes precedence) · CPC title

• G02B21/16 Primary

  adapted for ultraviolet illumination {; Fluorescence microscopes (G02B21/0076 takes precedence)} · CPC title

• G02B21/367

  providing an output produced by processing a plurality of individual source images, e.g. image tiling, montage, composite images, depth sectioning, image comparison · CPC title