Ophthalmologic Device Fixation Alignment Mechanism

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Solution Overview

Problem

Ophthalmologic apparatuses face challenges in acquiring data from a desired site of a subject's eye when the subject is not gazing at the fixation target, particularly due to issues like poor visual acuity or involuntary eye movement, leading to fixation loss.

Innovation Solution

The apparatus includes a movement mechanism to align the subject's eye with the data acquisition unit, a notification system to inform about alignment status, and a display unit to guide the fixation position, allowing for automatic or manual adjustment to ensure the image region is within a predetermined range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a fixation target is presented to guide the subject's gaze, then the alignment between the subject's eye and data acquisition unit is improved, but fixation loss occurs when the subject has poor visual acuity or involuntary eye movement

Engineering Contradiction:
Improvealignment precisionVSAvoidfixation stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system continuously monitors the subject's gaze position by detecting the image region of the fundus and comparing it with the predetermined range. When deviation is detected (fixation loss), the system provides feedback by displaying a notification to the subject and automatically adjusts the presentation position of the fixation target to maintain proper alignment and ensure reliable data acquisition.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system automatically detects fixation loss conditions and self-corrects by adjusting the fixation target position without requiring manual intervention. The notification unit and position adjustment mechanism work autonomously to maintain measurement reliability, allowing the system to service itself during the examination process.

Inventive Principle:
Principle #25Self-service

2Device complexity

If the fixation target position is fixed, then the device complexity is reduced, but the adaptability to different subject conditions (visual acuity, eye movement) deteriorates

Engineering Contradiction:
Improvefixation system complexityVSAvoidadaptability to subject conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The fixation target transitions from a static position to a dynamic one that automatically adjusts based on real-time detection of the subject's gaze position. The system changes the presentation position of the fixation target in response to detected fixation loss, enabling adaptation to different subject conditions while maintaining a relatively simple overall device structure.

Inventive Principle:
Principle #15Dynamics

3Productivity

If automatic data acquisition is implemented, then the productivity is improved, but the reliability deteriorates when fixation loss occurs without detection

Engineering Contradiction:
Improvedata acquisition speedVSAvoiddata quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system incorporates a determination unit that continuously monitors whether the image region is within the predetermined range, providing feedback on fixation quality. This feedback mechanism ensures that automatic data acquisition only proceeds when proper fixation is confirmed, preventing unreliable data collection while maintaining high productivity through automated operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary detection of fixation status before initiating data acquisition. By checking whether the image region is within the predetermined range in advance, the system ensures that data acquisition only occurs under reliable fixation conditions, preventing wasted time on invalid measurements while maintaining efficient automatic operation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3733049B1Ophthalmologic device and control method for same
Publication Date: 2025.01.15 TOPCON CORPORATION
  • EP3733049B1 patent drawingFigure 1
  • EP3733049B1 patent drawingFigure 2
  • EP3733049B1 patent drawingFigure 3

AI summary

An ophthalmologic device according to an embodiment optically acquires fundus data of an eye being examined. The ophthalmologic device comprises a fixation system, an image acquisition unit, a specification unit, and a determination unit. The fixation system projects fixation light into a subject's eye. The image acquisition unit acquires a fundus image of the eye being examined while the fixation light is being projected by the fixation system. The specification unit analyzes the image acquired by the image acquisition unit to specify an image region corresponding to a predetermined site on the fundus. The determination unit determines whether or not the image region specified by the specification unit is included in a predetermined range in the image acquired by the image acquisition unit.