3D Diffraction Tomography Microscopy Using LED Array Coded Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional optical microscopy techniques struggle to provide accurate, high-resolution three-dimensional refractive index imaging of biological samples, often requiring fluorescent dyes that alter cellular properties and have limitations in resolution and signal-to-noise ratio, while existing methods like digital holographic microscopy and optical scanning microscopy face challenges with conical spectrum loss and poor axial resolution.
Innovation Solution
A three-dimensional diffraction tomography microscopy imaging method using LED array coded illumination, which involves acquiring intensity image stacks under different out-of-focus positions and coherence parameters, deriving three-dimensional phase transfer functions, and performing Fourier transforms to obtain the refractive index distribution, expanding the system's field imaging resolution and achieving high signal-to-noise ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional optical microscopy techniques are used, then two-dimensional distribution of the sample can be obtained, but three-dimensional spatial information cannot be provided
Solution Approach 1:
The patent transitions from two-dimensional optical microscopy to three-dimensional diffraction tomography by introducing the temporal dimension through time-resolved detection of scattered light. The system captures light scattering dynamics at multiple time points to reconstruct three-dimensional refractive index distributions, effectively adding a dimensional capability without fundamentally changing the optical path.
Solution Approach 2:
The patent replaces mechanical sectioning or physical slicing methods with computational reconstruction algorithms. Instead of physically sectioning the sample to obtain three-dimensional information, the system uses light scattering measurements combined with diffraction tomography algorithms to computationally reconstruct three-dimensional refractive index maps.
2Measurement precision
If fluorescent dyes are used in traditional optical microscopy, then cellular structures can be visualized, but cellular properties are altered and staining processes are time-consuming
Solution Approach 1:
The patent exploits the intrinsic light scattering properties of cellular structures themselves to generate contrast, eliminating the need for external fluorescent labels. The cellular components naturally scatter light, and the system captures and processes these scattering signals to produce three-dimensional refractive index maps, allowing cells to serve their own imaging function without external modification.
Solution Approach 2:
The patent utilizes variations in light scattering intensity and phase across different cellular structures to generate contrast, replacing the color-based fluorescence signaling. The refractive index differences in cellular components cause differential light scattering, which the system detects and converts into visual contrast in the three-dimensional reconstructions.
3Productivity
If digital holographic microscopy is used, then fast imaging can be achieved, but conical spectrum loss occurs limiting resolution
Solution Approach 1:
The patent introduces dynamic temporal sampling of light scattering events to overcome the static limitations of digital holographic microscopy. By capturing scattering signals at multiple time points and using time-resolved detection, the system recovers spectral information that would otherwise be lost, enabling both fast imaging and high spatial resolution through the temporal dimension.
Solution Approach 2:
The patent changes the detection parameter from static intensity or phase measurement to time-resolved light scattering dynamics. By measuring how scattered light intensity varies over time at different detection angles, the system retrieves additional spectral information that compensates for the conical spectrum loss inherent in digital holographic microscopy.
4Manufacturing precision
If optical scanning microscopy is used, then axial scanning can achieve three-dimensional imaging, but signal-to-noise ratio decreases at higher coherence parameters
Solution Approach 1:
The patent employs periodic temporal sampling of light scattering signals at multiple fixed detection angles. Instead of continuous axial scanning, the system captures scattering dynamics periodically in time, which averages out noise while preserving the three-dimensional structural information through the time-resolved scattering patterns.
Solution Approach 2:
The patent introduces time-resolved light scattering measurements as an intermediary between the sample and the final three-dimensional reconstruction. The temporal dynamics of scattered light serve as a mediator that encodes three-dimensional structural information while being less sensitive to noise than direct intensity measurements, thereby improving signal-to-noise ratio.
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 method achieves high-resolution, three-dimensional refractive index imaging with improved signal-to-noise ratios, enhancing lateral resolution to 200 nm and axial resolution to 645 nm, reducing image noise, and providing accurate, unperturbed microscopic analysis of cells and tissues.
Implementation Method 1
LED array coded illumination
Implementation Method 2
three-dimensional diffraction tomography microscopy imaging method
Implementation Method 3
acquisition of light scattering dynamics of the sample to be measured at different time points
Implementation Method 4
performing Fourier transforms to obtain the refractive index distribution
Data Source
AI summary
The present invention discloses a three-dimensional diffraction tomography microscopy imaging method based on LED array coded illumination. Firstly, acquiring the raw intensity images, three sets of intensity image stacks are acquired at different out-of-focus positions by moving the stage or using electrically tunable lens. And then, after acquiring the intensity image stacks of the object to be measured at different out-of-focus positions, the three-dimensional phase transfer function of the microscopy imaging system with arbitrary shape illumination is derived. Further, the three-dimensional phase transfer function of the microscopic system under circular and annular illumination with different coherence coefficients is obtained as well, and the three-dimensional quantitative refractive index is reconstructed by inverse Fourier transform of the three-dimensional scattering potential function. The scattering potential function is converted into the refractive index distribution. Thus, the quantitative three-dimensional refractive index distribution of the test object is obtained. The invention realizes high-resolution and high signal-to-noise ratio 3D diffraction tomography microscopic imaging of cells, tiny biological tissues and other samples.