Cumulant Microscopy for Super-Resolution Imaging

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Solution Overview

Problem

Current super-resolution microscopy techniques face limitations in achieving high resolution, functional information, and compatibility with commercially available microscopes, particularly in three-dimensional imaging and live-cell suitability, while also being affected by brightness imbalances and background noise.

Innovation Solution

The method employs higher-order statistics to characterize the blinking kinetics of single point-like emitters, estimating spatial distribution and molecular brightness to extract microenvironment-related properties, combining cumulant and localization-based techniques, and using illumination-induced fluctuations for enhanced resolution and contrast.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If higher-order cumulants analysis is used to achieve super-resolution, then resolution enhancement and noise reduction are improved, but brightness imbalances and heterogeneities are amplified

Engineering Contradiction:
Improveresolution enhancementVSAvoidbrightness imbalance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the parameter of cumulant order from fixed to variable, adapting the order based on signal-to-noise ratio and sample characteristics. This allows optimization between resolution enhancement and brightness imbalance amplification by selecting appropriate cumulant orders dynamically rather than using a fixed high order for all cases

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by using a combination of different cumulant orders rather than relying on a single high-order cumulant. This mixed approach captures both the resolution benefits of higher orders and the stability of lower orders, avoiding excessive amplification of brightness heterogeneities while maintaining super-resolution capability

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If long acquisition times are used to record thousands of images for PALM/STORM, then localization precision is improved, but productivity and live-cell suitability deteriorate

Engineering Contradiction:
Improvelocalization precisionVSAvoidacquisition time
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary action by pre-calculating and storing temporal autocorrelation functions and cumulant values during data acquisition. This preprocessing allows for faster post-processing and image reconstruction, reducing the overall acquisition time while maintaining localization precision through efficient algorithms

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent substitutes mechanical/image scanning systems with computational methods. By using cumulant analysis of temporal fluctuations in widefield or confocal microscopy data, it achieves super-resolution without the mechanical constraints and long acquisition times of traditional single-molecule localization methods

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

3Measurement precision

If structured illumination is used for SIM, then super-resolution is achieved, but device complexity increases

Engineering Contradiction:
Improvesuper-resolutionVSAvoidoptical setup complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by making the cumulant microscopy method compatible with standard widefield and confocal microscopes without requiring specialized structured illumination optics. The same basic microscope hardware can perform both conventional and super-resolution imaging by simply applying different analysis algorithms to the acquired data

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Measurement precision

If STED microscopy is used to achieve super-resolution, then imaging contrast is improved, but energy consumption and device complexity increase

Engineering Contradiction:
Improveimaging contrastVSAvoidexcitation source requirement
Core Design Contradiction:
Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The patent replaces the intense laser excitation and depletion beams of STED with standard fluorescence excitation combined with temporal fluctuation analysis. The super-resolution and contrast enhancement are achieved through computational processing of temporal statistics rather than through high-energy optical fields

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

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 provides super-resolution imaging with improved contrast, functional information, and intrinsic 3D capability, suitable for live-cell imaging, while correcting brightness imbalances and expanding the range of suitable probes, enabling multi-color, colocalization, and anisotropy analysis.

Implementation Method 1

These methods are based on a widefield fluorescence microscopy concept exploiting the stochastic blinking of individual fluorophores

Methodology Applied
Scientific EffectStochastic blinking:

Implementation Method 2

fluorescence microscopy, where the fluorescent labels are emitting light in a known statistical manner

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 3

SOFI is based on a pixel-wise auto- or cross-cumulant analysis, which yields a resolution enhancement that grows with the cumulant order in all three dimensions. Uncorrelated noise, stationary background as well as out-of-focus light are greatly reduced by the cumulant analysis

Methodology Applied
Scientific EffectCumulant analysis:

Implementation Method 4

the use of a modulated excitation along with synchronized detection to populate and sense the fast triplet state fluctuations

Methodology Applied
Scientific EffectTriplet state fluctuations:

Data Source

PatentEP2721441B1Cumulant microscopy
Publication Date: 2019.09.18 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
  • EP2721441B1 patent drawingFigure 1
  • EP2721441B1 patent drawingFigure 2
  • EP2721441B1 patent drawingFigure 3

AI summary

The invention describes a method and a microscopy system for imaging and analysing stochastically and independently blinking point-like emitters. A multiple-order cumulants analysis in conjunction with an established blinking model enables the extraction of super-resolved environment-related parameter maps, such as molecular state lifetimes, concentration and brightness distributions of the emitter. In addition, such parameter maps can be used to compensate for the non-linear brightness and blinking response of higher-order cumulant images - used for example in Super-resolution Optical Fluctuation Imaging (SOFI) - to generate a balanced image contrast. Structures that otherwise would be masked by brighter regions in the conventional cumulant image become visible in the balanced cumulant image. The invention furthermore provides a method for the spectral unmixing of multi- colour samples using spectral cross-cumulants.