Refractive Error Determination via Spatial Modulation

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Solution Overview

Problem

Existing methods for determining refractive error require an optometrist or ophthalmologist and sophisticated equipment, which are not always accessible, especially for children, elderly, or those with communication barriers, and are costly to maintain.

Innovation Solution

A method and device that display spatially modulated images to users, allowing them to indicate perception thresholds without the need for an optometrist or complex apparatus, using image parameters to determine refractive error through user reactions, which can be recorded and analyzed to calculate spherical and cylindrical refractive error values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional objective refractive error determination methods are used, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improverefractive error determination accuracyVSAvoidapparatus complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the core measurement function from complex autorefractive devices and implements it using simple camera-based imaging. The system captures retinal images through the pupil and analyzes spatial frequency patterns without requiring sophisticated optical measurement apparatus, thereby reducing device complexity while maintaining measurement capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical/optical measurement systems with a digital imaging and image processing system. Instead of using complex optical instruments to directly measure refraction, the system uses camera-based capture of retinal images and computational analysis to determine refractive error, substituting mechanical measurement with digital processing

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If traditional refractive error determination methods are used, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:

Improverefractive error determination accuracyVSAvoidoperational simplicity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent implements self-service operation by enabling users to perform refractive error measurement independently without requiring trained optometrists or ophthalmologists. The system provides automated image capture and analysis that can be performed by laypeople, transforming a previously professional-only service into a user-friendly self-test

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent introduces a digital image processing system as an intermediary between the user and the measurement process. The automated image analysis algorithm acts as a mediator that processes captured retinal images and calculates refractive error without requiring direct professional intervention, thereby simplifying operation while maintaining accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If sophisticated autorefractive devices are used, then measurement precision is improved, but loss of energy increases

Engineering Contradiction:

Improverefractive error determination accuracyVSAvoidmaintenance and operation expenses

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

The patent replaces expensive, maintenance-intensive autorefractive devices with a low-cost camera-based system. The imaging device uses standard camera technology that is significantly cheaper to purchase and operate, eliminating the need for costly maintenance while providing sufficient measurement precision for refractive error detection

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 simple, accessible determination of refractive error for all users, including children and the elderly, without the need for specialized personnel or equipment, providing an objective measure that can be used globally and potentially in augmented reality or mobile devices.

Implementation Method 1

the terms 'refraction' or 'refractive' refer to a bending of incident light entering the interior of the eye via the pupil

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS12016627B2Method and device for determining a refractive error

Publication Date: 2024.06.25 CARL ZEISS VISION INTERNATIONAL GMBH

AI summary

A method, a device, and a computer program product for determining a refractive error of an eye of a user are disclosed, as well as a method for producing a spectacle lens. The method for determining includes: displaying an image with a spatial modulation to the user; optionally, recording a reaction of the user to a variation of the spatial modulation over time; detecting a point in time at which a perception threshold of the user is reached; and determining the refractive error of the user from the spatial modulation, wherein the image contains a source image with several picture elements, wherein values for an image parameter are assigned to the picture elements, and wherein the spatial modulation is generated such that the values of the image parameter determine the values of a modulation parameter of the spatial modulation in the image.