Spectral Frequency Encoded Fluorescence Imaging Probe

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional fluorescence imaging through miniature flexible probes faces challenges due to the inability to incorporate a rapid beam scanning mechanism and limited optical fibers, resulting in difficulties in obtaining high-quality fluorescent images with a sufficient number of resolvable points.

Innovation Solution

The implementation of spectrally and frequency-encoded (SFE) fluorescence imaging techniques, which utilize wavelength-dependent frequency modulation of excitation light and a grating to disperse it onto the sample, allowing for a higher number of resolvable points within a small diameter probe, and the use of a reference interferometer signal for active feedback control to correct non-linear movements, eliminating the need for post-acquisition processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If fiber optic bundles are used for fluorescence imaging through miniature probes, then the probe can be miniaturized, but the number of resolvable points is limited

Engineering Contradiction:
Improveprobe diameterVSAvoidnumber of resolvable points
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical fiber bundle system with a spectrally encoded imaging system that uses a single optical fiber combined with spectral dispersion and Fourier transform processing. This substitution allows achieving high resolution (e.g., 1024 resolvable points) within a small probe diameter (e.g., 1.2 mm) by encoding spatial information spectrally rather than relying on multiple physical fibers

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

Solution Approach 2:

The patent introduces spectral encoding as an additional dimension to traditional spatial imaging. By dispersing light through a grating and using Fourier transform spectroscopy, the system maps spatial information onto the spectral domain, enabling high-resolution imaging through a single fiber without the physical constraints of multi-fiber bundles

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If a rapid beam scanning mechanism is incorporated at the distal end of miniature probes, then image quality improves, but device complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoidscanning mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical beam scanning mechanisms with spectral encoding and Fourier transform processing. Instead of physically scanning beams across the sample, the system uses a stationary optical setup where spectral dispersion and digital processing achieve the same imaging function, eliminating complex mechanical components at the distal end

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

Solution Approach 2:

The patent introduces spectral encoding as an intermediary between the simple optical fiber and the image detection process. The grating and Fourier transform processing act as intermediaries that convert simple optical signals into high-resolution images without requiring complex mechanical scanning mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If more optical fibers are incorporated into small diameter probes, then imaging resolution improves, but the probe flexibility decreases

Engineering Contradiction:
Improveimaging resolutionVSAvoidprobe flexibility
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the mechanical fiber bundle system with a single-fiber optical system combined with spectral encoding. This substitution maintains high imaging resolution while significantly improving probe flexibility, as a single optical fiber is much more flexible than bundles containing thousands of individual fibers

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

Solution Approach 2:

The patent changes the fundamental parameter of light transmission from multiple spatial channels (fiber bundles) to a single spatial channel with spectral encoding. This parameter change enables the system to achieve high resolution through spectral rather than spatial multiplexing, thereby improving flexibility

Inventive Principle:
Principle #35Parameter changes

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 enables high-quality fluorescence imaging with a high number of resolvable points, increased flexibility of the miniature probe, and elimination of pixilation artifacts, achieving image quality and maneuverability comparable to or exceeding that of fiber bundles, while allowing for active correction of non-linear movements during imaging.

Implementation Method 1

a grating to disperse it onto the sample

Methodology Applied
Scientific EffectDiffraction: Diffraction Grating

Implementation Method 2

use of a reference interferometer signal for active feedback control to correct non-linear movements

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP1945094B1Spectral- and frequency- encoded fluorescence imaging
Publication Date: 2018.09.05 THE GENERAL HOSPITAL CORP
  • EP1945094B1 patent drawingFigure 1
  • EP1945094B1 patent drawingFigure 2
  • EP1945094B1 patent drawingFigure 3

AI summary

A system and method for obtaining fluorescence images from a sample are provided. Broadband excitation light (302) is encoded with a wavelength-dependent frequency modulation and dispersed onto a sample (314), e.g. with a grating (316a), to simultaneously illuminate an entire image line. The frequency-encoded fluorescence emission is measured to provide one line of the image. Mechanical scanning along a direction orthogonal to the wavelength-encoded axis allows creation of a two-dimensional fluorescence image. The system and method is especially useful for obtaining fluorescence images via endoscopes, catheters, or small-diameter probes.