OCT System Galvanometer Switching Anterior Posterior Eye Imaging

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Solution Overview

Problem

Existing ophthalmic optical coherence tomography systems struggle with quickly switching between anterior and posterior eye segments for accurate imaging, leading to inaccurate measurements due to low resolution and instability, especially when dealing with different eye shapes and movements.

Innovation Solution

An ophthalmic optical coherence tomography system with a modular design featuring a Y-direction scanning unit, rotatable total-reflection mirrors, and optical path adjustment units allows for quick switching between anterior and posterior eye segment imaging by adjusting the optical path using a galvanometer and removable total-reflection mirrors, enabling precise focusing and real-time imaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a movable probe moved by a stepping motor is used to adjust the optical path, then imaging of the cornea and fundus can be realized, but the switching between anterior and posterior eye segments is slow and real-time imaging cannot be achieved

Engineering Contradiction:
Improveswitching speed between anterior and posterior eye segmentsVSAvoidoptical path adjustment mechanism
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent replaces the stepping motor-driven movable probe with a galvanometer-based optical scanning system. The galvanometer uses electromagnetic fields to rapidly deflect mirrors, substituting slow mechanical translation with fast electromagnetic actuation. This enables real-time switching between anterior and posterior eye segments while maintaining optical path adjustment capability.

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

Solution Approach 2:

The patent introduces dynamic optical path adjustment through galvanometer mirrors that can rapidly change orientation. Instead of a static probe position, the system dynamically redirects light paths using electrically controlled mirrors, enabling real-time adaptation to different imaging targets (cornea or fundus) without mechanical movement of the entire probe assembly.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If a single probe is used for imaging, then device complexity is reduced, but the imaging quality is bad because the cornea and fundus have different shapes and a single probe cannot focus at both locations

Engineering Contradiction:
Improveimaging quality and focusing precisionVSAvoidimaging module configuration
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent divides the imaging system into separate anterior eye segment imaging module and posterior eye segment imaging module. Each module is optimized for its specific target (cornea or fundus) with appropriate focusing optics. The galvanometer system selectively directs light to the appropriate module, achieving high-quality imaging for each segment without requiring a compromise single-probe design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a universal optical platform that can perform both anterior and posterior segment imaging through the galvanometer-based switching system. While the imaging modules are specialized, the overall system achieves multi-functionality by rapidly switching between modules, eliminating the need for physical probe changes while maintaining specialized imaging capabilities.

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

3Productivity

If the optical path is adjusted by moving a probe back and forth, then imaging at different depths is possible, but the measurement time is long and real-time imaging cannot be achieved

Engineering Contradiction:
Improveimaging speed and measurement efficiencyVSAvoidtime for optical path adjustment
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent replaces mechanical probe translation with electromagnetic galvanometer actuation. The galvanometer mirrors can deflect almost instantaneously compared to mechanical probe movement, reducing the optical path adjustment time from seconds to milliseconds. This enables real-time imaging and significantly improves measurement efficiency.

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

Solution Approach 2:

The patent employs rapid periodic switching between anterior and posterior segment imaging modes using the galvanometer system. Instead of continuous mechanical movement, the system performs rapid back-and-forth optical path switching at frequencies that enable real-time imaging capture, effectively creating periodic imaging cycles that appear continuous to the observer.

Inventive Principle:
Principle #19Periodic action

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 solution enables high-quality, real-time imaging of both anterior and posterior eye segments with improved lateral resolution, allowing for accurate eye axial length measurements and reducing measurement errors caused by eye movement.

Implementation Method 1

the Y-direction scanning unit reflects light received by the X-direction scanning unit into the anterior eye segment imaging module; when the Y-direction scanning unit is at a second rotation angle, the Y-direction scanning unit reflects the light received by the X-direction scanning unit into the posterior eye segment imaging module

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

the fiber coupler receives light scattered back by the sample arm, and the received light interferes with the light reflected back by the reference arm

Methodology Applied
Scientific EffectLight interference: Interference

Implementation Method 3

the total-reflection mirror reflects the light to the rotatable-adjustable total-reflection mirror; the rotatable-adjustable total-reflection mirror cooperates with the Y-direction scanning unit to reflect the light transmitted on the rotatable-adjustable total-reflection mirror to the dichroic mirror

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 4

the dichroic mirror reflects the light to the fundus lens

Methodology Applied
Scientific EffectDichroic reflection: Dichroic Filter

Implementation Method 5

the light is transmitted through the fundus lens into a human eye to be examined

Methodology Applied
Scientific EffectLight focusing: Lens

Implementation Method 6

An ophthalmic optical coherence tomography system with a modular design featuring a Y-direction scanning unit, rotatable total-reflection mirrors, and optical path adjustment units allows for quick switching between anterior and posterior eye segment imaging by adjusting the optical path using a galvanometer

Methodology Applied
Scientific EffectGalvanometer deflection: Galvanometer

Data Source

PatentEP2767220B1Ophthalmic optical coherence tomography system and imaging method for quick switching to realize anterior and posterior eye segments imaging
Publication Date: 2019.06.19 SHENZHEN CERTAINN TECH CO LTD
  • EP2767220B1 patent drawingFigure 1~2
  • EP2767220B1 patent drawingFigure 3~4
  • EP2767220B1 patent drawingFigure 5~6

AI summary

It is provided an ophthalmic optical coherence tomography system in the invention, the system comprising: an OCT interferometer primary module and a sample arm module, wherein the OCT interferometer primary module comprises an OCT light source, a fiber coupler, a reference arm, a detection module, an X-direction scanning unit, and a Y-direction scanning unit; the sample arm module comprises an anterior eye segment imaging module and a posterior eye segment imaging module; the Y-direction scanning unit is rotatable; when the Y-direction scanning unit is at a first rotation angle, the Y-direction scanning unit reflects the light received by the X-direction scanning unit into the anterior eye segment imaging module; and when the Y-direction scanning unit is at a second rotation angle, the Y-direction scanning unit reflects the light received by the X-direction scanning unit into the posterior eye segment imaging module. It is further provided a method for quick switching to realize anterior and posterior eye segments imaging in the invention, in which imaging at one time and quick switching for locations at different depths can be realized, and on this basis, the eye axial length can be measured accurately.