Wavefront Measurement Device for Pediatric Refractive Error Assessment

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Solution Overview

Problem

Current methods for determining refractive properties in children are challenging due to wide powers of accommodation, difficulty in maintaining stillness, and the intimidating nature of conventional optical apparatus, leading to inaccurate and unreliable measurements, especially with subjective refraction techniques and time-consuming retinoscopy.

Innovation Solution

A system and method utilizing a wavefront measurement device with a child-specific measurement mode, featuring a display device showing a video with a moving fixation target and adjustable settings for pupillary and cornea vertex distances, allowing for quick and objective refractive property determination without requiring advanced skill or cooperation from the child.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If subjective refraction techniques are used to determine refractive properties in children, then the measurement can be performed with conventional optical apparatus, but the results are inaccurate and unreliable due to wide powers of accommodation and difficulty in maintaining stillness

Engineering Contradiction:
Improverefractive measurement accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces subjective refraction techniques and conventional optical apparatus with wavefront measurement technology. This substitution eliminates the need for child cooperation and accommodation control, providing objective, automated measurements that are both accurate and reliable for pediatric patients.

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

Solution Approach 2:

The wavefront measurement system performs automated objective refraction without requiring the child's active participation or response. The system independently captures wavefront data and calculates refractive properties, making the measurement process reliable even when the child cannot maintain stillness or cooperate.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If retinoscopy is used to determine refractive properties in children, then the measurement can be performed objectively, but the process is time-consuming and requires advanced skill

Engineering Contradiction:
Improverefractive measurement accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces manual retinoscopy with automated wavefront measurement technology. This substitution eliminates the need for examiner skill and significantly reduces measurement time while maintaining objective accuracy, making pediatric refraction both quick and reliable.

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

Solution Approach 2:

The wavefront measurement system acts as an intermediary between the light source and the refractive measurement, capturing wavefront data that automatically provides refraction information without requiring the time-consuming manual procedures of retinoscopy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If conventional optical apparatus is used for refractive measurement in children, then the equipment is familiar and easy to operate, but the apparatus is intimidating to children leading to movement and measurement errors

Engineering Contradiction:
Improveoperator convenienceVSAvoidrefractive measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces conventional optical apparatus with wavefront measurement technology that is less intimidating to children. This substitution maintains ease of operation through automation while improving measurement precision by eliminating movement-related errors.

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

4Extent of automation

If wavefront measurement is used to determine refractive properties in children, then automated and objective results are obtained, but the system complexity increases

Engineering Contradiction:
Improvemeasurement automationVSAvoidmeasurement system complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The wavefront measurement system serves multiple functions: it captures wavefront data, automatically calculates refractive properties, and provides results without requiring child cooperation. This multi-functionality justifies the increased complexity by delivering both automation and accuracy simultaneously.

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

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 reliable, quick, and fully automated refractive property assessment in children, replacing retinoscopy with wavefront measurement, providing accurate and reproducible results for refractive error correction.

Implementation Method 1

The objective refraction method is based on determining the wavefront of a propagating light bundle

Methodology Applied
Scientific EffectWavefront measurement: Light

Implementation Method 2

The display device is configured to show a video comprising the fixation target, wherein the video is a series of images shown with a frequency of at least 20 images per second

Methodology Applied
Scientific EffectVideo display: Light

Data Source

PatentEP3692890B1Method and system for determining the refractive properties of an eye of a child
Publication Date: 2023.04.26 CARL ZEISS VISION INTERNATIONAL GMBH
  • EP3692890B1 patent drawingFigure 1
  • EP3692890B1 patent drawingFigure 2
  • EP3692890B1 patent drawingFigure 3

AI summary

The current invention is directed to a system (30) for determining the refractive properties of an eye (10), the system (30) comprising a wavefront measurement device (32) for measuring the refractive properties of the eye (10), characterized in that the system (30) is configured to have at least one measurement mode assigned to children, wherein the system (30) has an input device (34) configured to switch the system (30) into one of the at least one measurement mode assigned to children, and wherein the system (30) is further configured to alter at least one of a group consisting of a default pupillary distance (54), a default cornea vertex distance (52), a default position (33) of the wavefront measurement device (32), a default position and/or direction of a measurement ray (58) of the wavefront measurement device (32), a default position (47) of a forehead and chin rest assembly (40) of the system (30) and a fixation target (38) when the system (30) is switched into the one of the at least one measurement mode assigned to children.