Determination of deflection of a microscope slide

Patent metadata

Field	Value
Publication number	US-10317663-B2
Application number	US-201514634465-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Feb 27, 2015
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

The present approach relates to the measure of the planar tilt of a slide on a microscope using an integrated auto-focuser. The tilt of the slide can be used to detect improperly loaded slides (i.e. if the slide is resting on either the cover-slip or a printed barcode), compensate for misalignment between the microscope optical axis and the slide, and reduce subsequent focusing times.

First claim

The invention claimed is:

1. A digital microscopy imaging system, comprising:
a stage configured to hold a slide;
an objective and image sensor configured to acquire images of a portion of the slide, when present;
a position controller configured to move one or both of the objective and the stage relative to one another in accordance with an imaging protocol;
a controller configured to control operation of one or both of the position controller and the image sensor;
a laser autofocuser configured to emit a ranging beam toward the stage;
a memory storing one or more routines; and
a processing component configured to execute the one or more routines stored in the memory, wherein the one or more routines, when executed by the processing component, cause acts to be performed comprising:
acquiring a plurality of autofocus measurements using the laser autofocuser, wherein autofocus measurements are acquired at different fixed locations relative to the slide, when present, by scanning the laser autofocuser through transition interfaces at each of the different fixed locations, and wherein the fixed locations are independent of the presence or absence of a tissue sample at the fixed locations;
determining at least one of a slide top or a slide bottom at each of the different fixed locations based on the autofocus measurements;
fitting a surface to the plurality of autofocus measurements; and
based on the fit of the surface to the plurality of autofocus measurements, deriving a measure of the tilt of the slide relative to the slide holder.

2. The digital microscopy imaging system of claim 1 , wherein the one or more routines, when executed by the processing component, cause additional acts to be performed: comprising:
automatically generating one or more focus points for the objective based on the surface;
moving the objective based on the generated focus points;
acquiring images of the slide.

3. The digital microscopy imaging system of claim 2 , wherein the one or more routines, when executed by the processing component, cause additional acts to be performed: comprising:
upon removal and replacement of the slide on the stage, computing a shift and transform from a set of previous focus positions to account for a current shift; and
acquiring a second set of images based on the transformed set of focus positions.

4. The digital microscopy imaging system of claim 2 , wherein the one or more routines, when executed by the processing component, cause additional acts to be performed: comprising:
comparing the measure of the tilt of the slide to a comparison criterion; and
providing a notification if the tilt of the slide exceeds the comparison criterion.

5. The digital microscopy imaging system of claim 1 , wherein the surface comprises a plane or a second order surface.

6. The digital microscopy imaging system of claim 1 , wherein the plurality of autofocus measurements comprises five or more autofocus measurements and wherein the surface comprises a second-order surface.

7. The digital microscopy imaging system of claim 1 , wherein the one or more routines, when executed by the processing component, cause further acts to be performed comprising:
comparing the measure of the tilt of the slide to a comparison criterion; and
providing a notification if the tilt of the slide exceeds the comparison criterion.

8. The digital microscopy imaging system of claim 7 , wherein comparing the measure of the tilt of the slide to the comparison criterion comprises determining if the measure of the tilt is within a focusing range of an objective lens.

9. The digital microscopy imaging system of claim 7 , wherein the comparison criterion is determined by dividing a depth of focus by a field of view size for a given objective lens.

Assignees

• Gen Electric

Inventors

• Corwin Alex David

Classifications

• G02B21/244

  using image analysis techniques · CPC title

• G02B21/365 Primary

  Control or image processing arrangements for digital or video microscopes (G02B21/361, G02B21/362 take precedence) · 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