Fundus Imaging Wavefront Adjustment via Fluorescence Feedback

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Solution Overview

Problem

Existing fundus imaging technologies face challenges in effectively compensating for optical aberration caused by the eye's front components without using a wavefront sensor.

Innovation Solution

A fundus imaging apparatus and method that employs a wavefront adjuster to optimize the wavefront of a femtosecond pulsed laser beam, maximizing fluorescence intensity detected by a detector, thereby converging the laser beam to the focal point with minimal optical aberration, using a deformable mirror and liquid crystal elements in the wavefront adjuster.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a wavefront sensor is used to compensate for optical aberration, then the optical aberration compensation accuracy is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveoptical aberration compensation accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the wavefront sensor from the optical aberration compensation system, replacing it with a fluorescence intensity detection mechanism. This eliminates the complex wavefront sensing hardware while achieving the same compensation goal through fluorescence signal optimization

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses the fluorescence signal from the ocular fundus itself as the feedback mechanism for wavefront optimization. The fluorescence intensity automatically indicates the quality of laser focusing, eliminating the need for external sensing devices

Inventive Principle:
Principle #25Self-service

2Measurement precision

If a wavefront sensor is used to compensate for optical aberration, then the optical aberration compensation accuracy is improved, but the cost increases

Engineering Contradiction:
Improveoptical aberration compensation accuracyVSAvoidcost
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent removes the expensive wavefront sensor component from the system, replacing it with a cost-effective fluorescence intensity detection approach that uses existing detector capabilities

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses readily available fluorescence detection capabilities rather than expensive specialized wavefront sensing hardware, achieving comparable performance at lower cost

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Productivity

If the laser beam is converged to the focal plate with maximum efficiency, then the fluorescence intensity is maximized, but optical aberration must be minimized

Engineering Contradiction:
Improvelaser beam convergence efficiencyVSAvoidoptical aberration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback loop where fluorescence intensity is measured and used to adjust the wavefront corrector, continuously optimizing the laser beam convergence to maximize productivity while minimizing optical aberration

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the wavefront corrector based on real-time fluorescence intensity measurements, allowing the laser beam convergence to adapt and optimize itself during operation

Inventive Principle:
Principle #15Dynamics

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 allows for accurate compensation of optical aberration, resulting in high-efficiency convergence of the laser beam and improved diagnostic accuracy of ocular fundus images without relying on a wavefront sensor.

Implementation Method 1

The wavefront adjuster is configured to adjust a wavefront of a femtosecond pulsed laser beam incident on an ocular fundus to be examined

Methodology Applied
Scientific EffectWavefront adjustment:

Implementation Method 2

a mechanism for correcting optical aberration, which occurs due to a cornea, a crystalline lens, etc., and the like

Methodology Applied
Scientific EffectOptical aberration compensation:

Implementation Method 3

The detector is configured to detect fluorescence generated in a multi-photon excitation process by the femtosecond pulsed laser beam incident on the ocular fundus

Methodology Applied
Scientific EffectMulti-photon excitation:

Implementation Method 4

detect fluorescence generated in a multi-photon excitation process

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 5

using a deformable mirror and liquid crystal elements in the wavefront adjuster

Methodology Applied
Scientific EffectDeformable mirror wavefront correction:

Implementation Method 6

using a deformable mirror and liquid crystal elements in the wavefront adjuster

Methodology Applied
Scientific EffectLiquid crystal optical modulation: Liquid Crystals

Data Source

PatentEP2497411B1Fundus imaging apparatus and fundus imaging method
Publication Date: 2019.04.03 SONY GROUP CORP
  • EP2497411B1 patent drawingFigure 1

AI summary

Provided is a fundus imaging apparatus including a wavefront adjuster and a detector. The wavefront adjuster is configured to adjust a wavefront of a femtosecond pulsed laser beam incident on an ocular fundus to be examined. The detector is configured to detect fluorescence generated in a multi-photon excitation process by the femtosecond pulsed laser beam incident on the ocular fundus to be examined. The wavefront adjuster is further configured to adjust the wavefront so that an intensity of the fluorescence to be detected by the detector becomes a maximum value.