Nematode Worm Tracking via Difference Image Extraction

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Solution Overview

Problem

Current methods for tracking nematode worms, such as Caenorhabditis elegans, are inefficient for large cohorts due to the complexity and resource-intensive nature of image data processing, storage, and energy consumption, especially when monitoring movement over extended periods.

Innovation Solution

A method involving transmission imaging to obtain difference images, selecting and tracking candidate worms by identifying maximum intensity differences, and updating images to reduce data complexity, allowing for efficient local processing and data compression, enabling accurate tracking with lower-specification imaging systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If imaging worms at regular time intervals to monitor movement, then measurement precision of worm movement is improved, but device complexity and data processing requirements increase significantly

Engineering Contradiction:
Improvemovement measurement precisionVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential information needed for worm tracking by computing difference images between consecutive frames and identifying only the positions of worms, rather than processing and storing all original image data. This extraction approach maintains measurement precision while dramatically reducing data processing complexity and storage requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the image processing task into distinct stages: background subtraction to isolate worms from the substrate, identification of worm positions through intensity difference analysis, and tracking of worm coordinates over time. This segmentation allows each stage to be optimized independently, reducing overall system complexity.

Inventive Principle:
Principle #1Segmentation

2Productivity

If tracking large numbers of worms over extended periods, then productivity of ageing studies is improved, but quantity of data generated increases exponentially

Engineering Contradiction:
Improvescreening efficiencyVSAvoidimage data volume
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent extracts only the critical data elements (worm position coordinates and movement metrics) from the full image sequences, discarding redundant pixel information. This allows high-productivity tracking of large worm cohorts while generating minimal data that requires only modest storage and processing resources.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent discards the majority of image data that does not contribute to worm tracking by using difference imaging and position extraction, while recovering and preserving only the essential movement information needed for ageing studies. This selective discarding and recovering approach enables scalable tracking of large numbers of worms.

Inventive Principle:
Principle #34Discarding and recovering

3Measurement precision

If using high-specification imaging systems to capture detailed worm images, then measurement precision is improved, but use of energy and space requirements increase

Engineering Contradiction:
Improveworm detection precisionVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by using simpler, lower-specification imaging equipment that captures only sufficient detail for worm detection and tracking. By combining this with difference imaging and position extraction, the system achieves adequate measurement precision while consuming significantly less energy and occupying less space than high-specification systems would require.

Inventive Principle:
Principle #16Partial or excessive action

4Measurement precision

If performing complex data processing locally to determine worm positions, then measurement precision is improved, but device complexity at the imaging system increases

Engineering Contradiction:
Improveposition determination precisionVSAvoidlocal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts position information directly from difference images using simple intensity thresholding and coordinate identification algorithms, rather than performing complex image analysis locally. This extraction approach maintains position determination precision while keeping the imaging system itself simple, with complex processing deferred to external computers.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables efficient tracking of large numbers of worms with significant data compression (over 100 times) while preserving image quality, reducing resource requirements and enabling real-time analysis, thus overcoming the limitations of existing methods.

Implementation Method 1

obtaining a first image of a field of view including the plurality of worms by transmission imaging

Methodology Applied
Scientific EffectTransmission imaging: Light

Data Source

PatentUS11756214B2Method and apparatus for tracking nematode worms
Publication Date: 2023.09.12 MAGNITUDE BIOSCIENCES LTD
  • US11756214B2 patent drawing
  • US11756214B2 patent drawing
  • US11756214B2 patent drawing

AI summary

A method for tracking movement of nematode worms comprises: (i) providing a plurality of worms on a translucent substrate; (ii) obtaining a first image of a field of view including the plurality of worms by transmission imaging; (iii) obtaining a first difference image of the plurality of worms corresponding to an intensity difference between said first image and a background image of the field of view; (iv) repeating the following steps (a) to (d) a plurality of N times, for n=1 to N: (a) determining, from the first difference image, an nth pixel corresponding to a maximum intensity difference; (b) selecting, from the first difference image, an nth block of pixels comprising the selected nth pixel; (c) determining a coordinate associated with the selected nth block of pixels; and (d) updating said first difference image by setting each pixel of said nth block of pixels in said first difference image to a value corresponding to a zero or low intensity difference; (v) obtaining a sequence of M subsequent images of the field of view by transmission imaging; and (vi) repeating the following steps (f) and (g) for each of the M subsequent images, for m=2 to m=M+1: (f) obtaining an mth difference image of the plurality of worms corresponding to an intensity difference between the mth subsequent image and said background image; and (g) repeating the following steps a plurality of N times, for n=1 to n=N: determining, from the mth difference image, an nth pixel corresponding to a maximum intensity difference or a centre of the intensity difference distribution of a trial block of pixels positioned at the determined coordinate associated with the corresponding nth selected block of pixels of the (m−1)th difference image; selecting an nth block of pixels of said mth difference image, said nth block of pixels comprising the determined nth pixel; and determining a coordinate associated with the selected nth block of pixels of said mth difference image.