Pipette Tip Imaging Alignment for Accurate Cell Colony Picking

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Solution Overview

Problem

Existing object picking instruments, such as pipette tips, face challenges in accurately positioning over objects due to dimensional differences, poor reproducibility in mounting, and limitations in robotic positional accuracy, leading to potential errors in picking adherent cell colonies.

Innovation Solution

An imaging-based system using a light source, camera, and objective to irradiate and capture emission light from both objects and pipette tips, allowing for precise alignment by analyzing positional errors and correcting the pipette tip's position relative to the selected object.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If conventional robotic positioning is used to move the pipette tip to the object, then the picking operation can be automated, but the positional accuracy is limited due to robotic positioning errors and dimensional variations

Engineering Contradiction:
Improveautomation of picking operationVSAvoidpipette tip positioning accuracy
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical positioning system with an optical imaging-based positioning system. Instead of relying on robotic arm positioning accuracy, the system uses a camera to capture images of both the object and pipette tip, then calculates their relative positions through image processing. This substitution of mechanical positioning with optical measurement resolves the contradiction by achieving high positioning accuracy independent of robotic positioning errors.

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

Solution Approach 2:

The patent creates optical copies (images) of both the object and pipette tip to determine their relative positions. By capturing images of both objects and the pipette tip and processing these optical copies, the system can accurately determine positional relationships without relying on mechanical positioning. This copying approach allows for precise alignment even when robotic positioning has errors.

Inventive Principle:
Principle #26Copying

2Device complexity

If dimensional variations between different pipette tips are not compensated, then the device complexity remains low, but the picking accuracy deteriorates due to poor reproducibility in mounting

Engineering Contradiction:
Improvesimplicity of pipette tip mountingVSAvoidpipette tip positioning reproducibility
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent implements a self-service positioning system where the imaging system automatically detects and compensates for pipette tip positioning variations. Instead of requiring complex mechanical mounting mechanisms to ensure precise positioning, the system allows pipette tips to be mounted with simple, reproducible actions and then uses image processing to detect and compensate for any dimensional variations. This self-correction approach resolves the contradiction by maintaining device simplicity while achieving high positioning reproducibility.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If optical sensors are used to locate the pipette tip relative to the robot arm, then positioning accuracy is improved, but errors still exist due to the separation between the sensor and the actual picking point

Engineering Contradiction:
Improvepipette tip location accuracyVSAvoidpositional error information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent merges the imaging of both the object and the pipette tip into a single optical field and image processing system. Instead of separately locating the pipette tip relative to the robot arm and then calculating positions, the system captures images of both the object and pipette tip together, processes them in the same coordinate system, and directly calculates their relative positions. This merging eliminates the need for complex coordinate transformations and reduces positional error information loss.

Inventive Principle:
Principle #5Merging (Combining)

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

Enhances the accuracy of pipette tip positioning over objects, reducing errors and improving the success rate of picking operations, especially in densely packed groups.

Implementation Method 1

the excitation light beam passes through the objective and irradiates the plurality of objects, the plurality of objects in response emits a first emission light beam

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

an imaging system configured to direct light from the light source to the objective and from the objective to the camera

Methodology Applied
Scientific EffectOptical focusing: Lens

Implementation Method 3

the camera receives the first emission light beam and in response outputs a first output signal, acquire an image of the plurality of objects by receiving and processing the first output signal

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP3655162B1Object picking apparatus with imaging-based locating of pipette tip
Publication Date: 2026.04.01 MOLECULAR DEVICES LLC
  • EP3655162B1 patent drawingFigure 1
  • EP3655162B1 patent drawingFigure 2
  • EP3655162B1 patent drawingFigure 3

AI summary

An object such as a cell colony may be picked from a plurality of objects by acquiring an image of the objects and an image of a pipette tip. The image of the objects is analyzed to select an object of interest. The selected object is associated with a coordinate position. Based on the coordinate position, the pipette tip is positioned over the selected object. An image of the pipette tip is then acquired and analyzed. The pipette tip is associated with a coordinate position. A positional error between the coordinate position of the selected object and the coordinate position of the pipette tip is determined. Based on the positional error, the pipette tip and/or a sample holder supporting the objects is moved to align the pipette tip over the selected object, by matching the coordinate position of the pipette tip with the coordinate position of the selected object.