Image-based tube top circle detection with multiple candidates

Patent metadata

Field	Value
Publication number	US-12254694-B2
Application number	US-201816630286-A
Country	US
Kind code	B2
Filing date	Jun 25, 2018
Priority date	Jul 11, 2017
Publication date	Mar 18, 2025
Grant date	Mar 18, 2025

Abstract

Embodiments provide a method of using image-based tube top circle detection based on multiple candidate selection to localize the tube top circle region in input images. According to embodiments provided herein, the multi-candidate selection enhances the robustness of tube circle detection by making use of multiple views of the same tube to improve the robustness of tube top circle detection. With multiple candidates extracted from images under different viewpoints of the same tube, the multi-candidate selection algorithm selects an optimal combination among the candidates and provides more precise measurement of tube characteristics. This information is invaluable in an IVD environment in which a sample handler is processing the tubes and moving the tubes to analyzers for testing and analysis.

First claim

We claim:

1. A method of image-based sample tube top circle detection across multiple images, the method comprising:
receiving, from at least one camera, a series of images of a tray, the tray comprising a plurality of tube slots, the tray holding a given sample tube in one of the plurality of tube slots;
extracting, using a processor, for the given sample tube a plurality of candidates in each image of the series of images;
computing, using the processor, a plurality of consistency scores, each of the plurality of consistency scores between candidates across images in the series of images from possible combinations of the plurality of candidates;
accumulating, using the processor, the plurality of consistency scores;
selecting, using the processor, a true tube top circle for the given sample tube for each image in the series of images based on a highest consistency score between candidates across images in the series of images;
analyzing the true tube top circle for the given sample tube to determine tube characteristics; and
determining a processing step for the given sample tube based on the determined tube characteristics.

2. The method of claim 1 , wherein computing the plurality of consistency scores comprises:
determining, using the processor, the possible combinations of the plurality of candidates;
determining, using the processor, properties for each of the possible combinations, the properties based on one or more of characteristics of respective ones of the plurality of candidates and characteristics of respective ones of the images; and
computing, using the processor, the plurality of consistency scores based on the determined properties.

3. The method of claim 1 , further comprising saving the determined properties in a lookup table.

4. The method of claim 2 , wherein the properties comprise one or more of circle diameter, circle center location, circle height, and circle center offset.

5. The method of claim 2 , wherein the characteristics of respective ones of the images comprise one or more of shape, color, and texture.

6. The method of claim 1 , wherein the tray is configured to fit within a portion of a drawer movable between an open position and a closed position and the series of images of the tray is acquired via the at least one camera as the drawer is moved between the open position and the closed position.

7. The method of claim 1 , wherein the series of images comprises a plurality of views of the given sample tube, each of the plurality of views at a different viewpoint.

8. The method of claim 1 , further comprising analyzing the true tube top circle for the given sample tube to determine tube categories.

9. A vision system for use in an in vitro diagnostics environment comprising:
a tray comprising a plurality of tube slots arranged in a matrix of rows and columns, each tube slot configured to receive a sample tube;
a surface configured to receive the tray;
at least one camera configured to capture a series of images of the tray; and
a processor configured to:
extract for a given sample tube a plurality of candidates in each image of the series of images;
compute a plurality of consistency scores, each of the plurality of consistency scores between candidates across images in the series of images from possible combinations of the plurality of candidates;
accumulate the plurality of consistency scores;
select a true tube top circle for the given sample tube for each image in the series of images based on a highest consistency score between candidates across the images in the series of images;
analyze the true tube top circle for the given sample tube to determine tube characteristics; and
determine a processing step for the given sample tube based on the determined tube characteristics.

10. The system of claim 9 , wherein computing the plurality of consistency scores comprises:
determining the possible combinations of the plurality of candidates;
determining properties for each of the possible combinations, the properties based on one or more of characteristics of respective ones of the plurality of candidates and characteristics of respective ones of the images; and
computing the plurality of consistency scores based on the determined properties.

11. The system of claim 10 , wherein the processor is further configured to save the determined properties in a lookup table.

12. The system of claim 10 , wherein the characteristics of respective ones of the images comprise one or more of circle diameter, circle center location, circle height, and circle center offset.

13. The system of claim 10 , wherein the properties comprise one or more of shape, color, and texture.

14. The system of claim 9 , wherein the surface comprises a portion of a drawer movable between an open position and a closed position and the series of images of the tray is acquired via the at least one camera as the drawer is moved between the open position and the closed position.

15. The system of claim 9 , wherein the series of images comprises a plurality of views of the given sample tube, each of the plurality of views at a different viewpoint.

16. The system of claim 9 , wherein the processor is further configured to analyze the true tube top circle for the given sample tube to determine tube categories.

Assignees

• Siemens Healthcare Diagnostics Inc

Inventors

• Chang Yao-Jen
• Kluckner Stefan
• Pollack Benjamin S
• Chen Terrence

Classifications

• G01N2035/0498

  Drawers used as storage or dispensing means for vessels or cuvettes · CPC title

• G01N2035/0418

  Plate elements with several rows of samples · CPC title

• G01N35/04

  Details of the conveyor system {(G01N35/021 - G01N35/028 take precedence)} · CPC title

• G01N35/00732

  Identification of carriers, materials or components in automatic analysers · CPC title

• G01N21/253

  for batch operation, i.e. multisample apparatus (analytical automats G01N35/00) · CPC title