Live Cell Focus Tracking and Image Matching for Drift Compensation

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Solution Overview

Problem

Existing live cell observation systems face challenges in maintaining accurate focus and image matching due to mechanical precision limitations and accumulated errors, leading to poor image quality and spatial correspondence issues during long-term observation.

Innovation Solution

A method involving motion calibration and compensation using Gaussian blur processing, Laplacian algorithm for sharpness calculation, phase correlation for image matching, and fault tolerance processing to ensure accurate focus tracking and image alignment, even with dynamic cell changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-precision three-dimensional mechanical motion platforms are used to capture cell images, then initial positioning accuracy is improved, but accumulated errors and mechanical precision limitations cause focus deviation and image misalignment during long-term observation

Engineering Contradiction:
Improveinitial positioning accuracyVSAvoidfocus stability during long-term observation
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent implements feedback mechanisms by capturing images at different Z-axis positions, evaluating image sharpness through Laplacian variance calculation, and automatically adjusting the Z-axis position based on the sharpness evaluation results. This closed-loop feedback system continuously corrects focus drift caused by mechanical errors during long-term observation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces reliance on mechanical precision with image processing and algorithmic methods. Instead of depending solely on mechanical stability, the system uses Laplacian variance calculation and phase correlation algorithms to detect and correct positioning errors, substituting mechanical reliability with computational accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If the Z-axis is moved to different positions for focusing, then focus adjustment is achieved, but image sharpness evaluation and optimal focal plane identification become complex

Engineering Contradiction:
Improvefocus adjustment capabilityVSAvoidsharpness evaluation process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent transforms the complex quality assessment problem into a simple parameter optimization problem by using Laplacian variance as a quantitative metric. The system automatically adjusts the Z-axis position to maximize this parameter, converting subjective focus evaluation into an objective mathematical optimization task

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system performs self-adjustment by automatically capturing images at different Z-positions, calculating Laplacian variances, identifying the maximum value, and returning to that optimal position. This self-service mechanism eliminates the need for manual focus adjustment and complex external evaluation procedures

Inventive Principle:
Principle #25Self-service

3Speed

If XYZ axes are positioned at target observation points with initial focusing, then positioning speed is improved, but field-of-view shift along X and Y axes causes lack of spatial correspondence between sequentially captured images

Engineering Contradiction:
Improvepositioning speedVSAvoidspatial correspondence accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical positioning precision with image processing methods. Instead of relying on mechanical stability to maintain spatial correspondence, the system uses phase correlation algorithms to calculate translation relationships between images and computationally correct any misalignment, achieving sub-pixel accuracy independent of mechanical precision

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces image processing algorithms as an intermediary between the mechanical positioning system and the final image analysis. The phase correlation algorithm acts as a mediator that translates mechanical positions into accurate spatial relationships, decoupling the speed benefits of mechanical positioning from the precision requirements of image matching

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Ensures stable and sharp cell imaging by maintaining accurate focus and spatial correspondence across multiple captures, enhancing data reliability and system robustness.

Implementation Method 1

calculating sharpness through a Laplacian algorithm... performing second-order differential operations on the Gaussian-blurred image through a discrete form of a Laplacian operator

Methodology Applied
Scientific EffectLaplacian operator:

Implementation Method 2

calculating a translation relationship between the two images through a phase correlation algorithm

Methodology Applied
Scientific EffectPhase correlation:

Data Source

PatentEP4668210A1Live cell image capture focus tracking and image matching method, and use thereof
Publication Date: 2025.12.24 SHENZHEN SHENGQIANG TECH
  • EP4668210A1 patent drawingFigure 1
  • EP4668210A1 patent drawingFigure 2
  • EP4668210A1 patent drawing

AI summary

The present disclosure provides a method for focus tracking and image matching in live cell imaging and an application thereof. The method includes moving three XYZ axes to an observation point accurately, moving upward and downward and recording multi-stage positions and images, and determining an optimal focal plane of the Z axis through Gaussian blur and a Laplacian algorithm; and calculating a translation relationship between the images for calibration and compensation through a phase correlation algorithm in combination with Fourier transform and affine transformation in X and Y axes positioning. In addition, a fault tolerance mechanism is included. When focusing or matching fails, multiple attempts are made and verification is performed through the phase correlation algorithm, to cope with hardware anomalies or environmental changes, such that imaging accuracy is ensured. A set step size is in a range of 5 to 10 minimum step sizes. The method can improve the accuracy and stability of live cell observation.