Multispectral Retinal Fluorescence Imaging Without a Spectrometer
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Solution Overview
Problem
Existing fluorescence imaging techniques struggle to combine spectral and spatial information of the retina effectively, requiring expensive equipment and risking phototoxicity with multiple flashes.
Innovation Solution
A system using optical filters and cameras captures fluorescence images without a spectrometer, combining images from different wavelength bands to achieve high-spatial accuracy and reduce phototoxicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a complex spectrometer is used to detect fluorescence spectra, then spectral information can be obtained, but device complexity and cost increase significantly
Solution Approach 1:
The patent divides the spectral detection task into multiple discrete wavelength bands (e.g., blue, cyan, green, yellow-green, yellow, orange, red) using separate narrowband optical filters. Each filter captures a specific portion of the fluorescence spectrum, and the results are later combined to reconstruct the full spectral profile. This segmentation replaces the need for a complex spectrometer with simpler, specialized filters for each wavelength range.
Solution Approach 2:
The patent implements a nested filter structure where multiple narrowband optical filters are placed in sequence within the optical path. Each filter is nested within the previous one, creating a multi-stage filtering system that progressively narrows down the wavelength range. This nested arrangement allows for precise spectral selection without requiring complex spectrometer hardware.
2Measurement precision
If passband filtering is applied to capture spectral information, then spectral data can be obtained, but light efficiency decreases and phototoxicity increases
Solution Approach 1:
The patent uses narrowband optical filters with relatively wide passbands compared to traditional spectrometer slit widths. Each filter captures a broader portion of the spectrum than a traditional spectrometer would at the same resolution setting, thereby collecting more light. The cumulative effect of multiple overlapping filters provides sufficient spectral information while maintaining high light efficiency and reducing phototoxicity.
3Measurement precision
If traditional fluorescence imaging is used, then spectral data can be captured, but spatial information is lost
Solution Approach 1:
The patent merges spectral filtering with conventional widefield fluorescence imaging by placing narrowband optical filters in the optical path of a standard camera system. This combination allows the system to capture both spatial information (through the camera's pixel array) and spectral information (through the wavelength-selective filters) simultaneously in a single image, eliminating the trade-off between the two types of data.
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
Enables efficient fluorescence imaging with high-spatial accuracy and reduced phototoxicity using simple equipment, allowing for better disease diagnosis.
Implementation Method 1
one or more optical filters configured to transmit light within a first wavelength band and block light outside the first wavelength band
Implementation Method 2
a beam splitter configured to divide incident light into a first set of reflected light and a second set of reflected light
Implementation Method 3
Some features correspond to healthy eye anatomy or pathologies exhibit fluorescence when illuminated
Data Source
AI summary
In certain embodiments, a system, a computer-implemented method, and computer-readable medium are disclosed for light efficient fluorescence imaging. The retina is flashed with broadband light and returned light is imaged after passing through one or more filters, such as notch filers, low-pass filters, and high-pass filters. Images may be captured with a single camera or at least two cameras, one capturing transmitted light from the filter and the other capturing returned light. Images may be combined by subtraction and/or addition to obtain a combined image representing light within a passband whereas no passband filters are used during imaging.