Ophthalmic Pupil Alignment Using Dual Fixation Targets

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Solution Overview

Problem

Existing ophthalmologic imaging systems, particularly OCT devices, require complex and costly alignment processes that rely on trained operators or automated systems, which are not suitable for self-administered procedures like at-home use, and lack effective self-alignment mechanisms.

Innovation Solution

A system and method utilizing first and second fixation targets with different optical characteristics, spatially filtered by apertures and filters, providing intuitive feedback to subjects for aligning their pupils with the imaging device, allowing self-alignment and reducing reliance on external operators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If automated alignment systems are used, then alignment precision is improved, but device complexity and manufacturing costs increase

Engineering Contradiction:
Improvealignment precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system enables subjects to perform self-alignment using fixation targets and visual feedback mechanisms. The subject adjusts their own positioning by observing the alignment indicators, eliminating the need for external operators or complex automated positioning systems while maintaining high alignment precision.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system provides real-time visual feedback through alignment indicators and fixation targets that show the subject whether their pupil is properly aligned with the imaging device. This feedback loop allows the subject to make precise adjustments without requiring complex automated control systems.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If operator training is provided, then alignment competency is improved, but operational time and cost increase

Engineering Contradiction:
Improvealignment competencyVSAvoidtraining time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The alignment system is designed to be intuitively operable by subjects without requiring trained operators. The self-aligning mechanism with visual feedback enables anyone to achieve proper alignment through self-instruction, eliminating the need for extensive operator training while maintaining high alignment competency.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If self-alignment mechanism is implemented, then ease of operation is improved, but alignment precision may deteriorate

Engineering Contradiction:
Improveself-alignment capabilityVSAvoidalignment precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system incorporates multiple visual feedback indicators including fixation targets and alignment markers that provide real-time information to the subject about their positioning accuracy. This feedback enables the subject to achieve high-precision alignment through self-adjustment without sacrificing alignment quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses multiple fixation targets and redundant visual indicators that provide more alignment information than strictly necessary. This excessive visual feedback ensures that even subjects with limited dexterity or visual acuity can achieve precise alignment, maintaining high precision while maximizing ease of operation.

Inventive Principle:
Principle #16Partial or excessive 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

Enables subjects to align ophthalmologic devices with high precision and ease, reducing costs and complexity, facilitating self-administered procedures, and enhancing safety by minimizing operator interaction.

Implementation Method 1

first and second fixation targets located in a first plane and respectively configured to transmit light having first and second optical characteristics

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

first and second apertures located in a second plane and configured to spatially filter the light transmitted from the first and second fixation targets

Methodology Applied
Scientific EffectSpatial filtering: Filter (optical)

Implementation Method 3

first and second filters located approximately in the second plane, the first filter configured to optically filter the spatially filtered light from the first fixation target to have the first optical characteristic

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Implementation Method 4

at least one lens configured to image the first and second apertures in the second plane to a third plane approximately corresponding to the subject's pupil

Methodology Applied
Scientific EffectOptical imaging: Lens

Implementation Method 5

based upon the ophthalmologic device being misaligned with the subject's pupil in approximately the third plane, the subject's pupil blocks the image of at least one of the first and second apertures

Methodology Applied
Scientific EffectLight blocking: Filter (optical)

Implementation Method 6

light from the first light source of the ophthalmologic device enters the subject's pupil, is reflected or scattered by the subject's retina, exits the subject's pupil, and is received by the image sensor

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentEP4447781B1System and method for assisting a subject with alignment to an ophthalmologic device
Publication Date: 2025.11.26 CARL ZEISS MEDITEC INC
  • EP4447781B1 patent drawingFigure 1
  • EP4447781B1 patent drawingFigure 2A~2B
  • EP4447781B1 patent drawingFigure 3A~3B

AI summary

A system for assisting a subject with alignment with an ophthalmologic device that includes a first light source and an image sensor. The system includes first and second fixation targets located in a first plane to transmit light having first and second optical characteristics. Also, first and second apertures are located in a second plane and configured to spatially filter the light transmitted from the first and second fixation targets. At least one lens configured to image the first and second apertures in the second plane to a third plane approximately corresponding to the subject's pupil, wherein, based upon the ophthalmologic device being misaligned with the subject's pupil in the third plane, the subject's retina receives an image of at most one of the first and second fixation targets.