Ocular Surface Wave Measurement for Comfortable Non-Contact Tonometry

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Solution Overview

Problem

Existing non-contact intraocular pressure measurement methods using air puffs or ultrasonic vibrations cause discomfort, scatter ocular adherents, require high ultrasonic power, and suffer from alignment issues affecting measurement stability and accuracy.

Innovation Solution

A non-contact ocular physical property measuring device that generates and detects surface waves on the eyeball using amplitude-modulated ultrasonic waves or pulsed light, calculating intraocular pressure and material properties based on phase velocity without causing discomfort or requiring high power, and aligns excitation and detection points for stable measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If air puff is used to deform the cornea for non-contact intraocular pressure measurement, then intraocular pressure can be measured without contact, but the air puff causes discomfort to the patient and scatters adherents on the ocular surface

Engineering Contradiction:
Improvemeasurement accuracyVSAvoiddiscomfort and contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical air puff system with an optical interference measurement system. Instead of using air pressure to deform the cornea, the system uses light waves to detect corneal surface shape changes during natural blinking, thereby eliminating the harmful effects of air puffs while maintaining measurement capability

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

Solution Approach 2:

The patent introduces light waves as an intermediary to measure corneal deformation indirectly. By shining light on the cornea and analyzing the reflected interference patterns, the system can detect subtle shape changes without applying physical force, thus avoiding discomfort and contamination

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If strong ultrasonic waves are used to vibrate the eyeball for non-contact tonometry, then intraocular pressure can be measured, but high ultrasonic power is required which complicates the device and increases energy consumption

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidultrasonic power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the ultrasonic vibration system with an optical interference detection system. Instead of using high-power ultrasonic waves to vibrate the eyeball, the system uses low-power light waves to optically detect corneal surface changes, dramatically reducing energy consumption while maintaining measurement capability

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

Solution Approach 2:

The patent utilizes the natural mechanical vibration of the cornea during blinking rather than inducing vibration through external ultrasonic forces. By detecting the corneal shape changes that occur naturally during blinking, the system eliminates the need for high-power ultrasonic excitation

Inventive Principle:
Principle #18Mechanical vibration

3Measurement precision

If ultrasonic waves are focused on a specific point on the eyeball for measurement, then measurement precision can be improved, but alignment between excitation and detection points becomes critical and difficult to maintain

Engineering Contradiction:
Improvelocal measurement accuracyVSAvoidalignment requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the optical system serve multiple functions simultaneously: the same light source and detection system used for measuring corneal curvature is also used for detecting surface shape changes during blinking. This eliminates the need for separate excitation and detection alignment systems, reducing device complexity while maintaining measurement precision

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

Solution Approach 2:

The patent merges the curvature measurement function and the intraocular pressure measurement function into a single optical interference detection system. By combining these functions, the system eliminates the need for separate alignment mechanisms, thereby reducing device complexity while maintaining local measurement accuracy

Inventive Principle:
Principle #5Merging (Combining)

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 stable, accurate, and comfortable intraocular pressure and material property measurements without vibrations, reducing the influence of amplitude changes and external factors, and allowing for compact device design.

Implementation Method 1

an excitation part that excites at least one or more excitation points on an eyeball by using an irradiation wave to generate a surface wave on a surface of an eye to be examined

Methodology Applied
Scientific EffectSurface wave generation: Surface Acoustic Wave

Implementation Method 2

a detection part that detects the surface wave generated by the excitation part at at least one or more detection points, which are different from the excitation points, on the eyeball

Methodology Applied
Scientific EffectSurface wave detection: Surface Acoustic Wave

Implementation Method 3

a surface wave processing part that analyzes the surface wave detected by the detection part

Methodology Applied
Scientific EffectPhase velocity measurement:

Implementation Method 4

an ocular physical property calculation part that calculates physical properties of the eyeball based on the analyze result by the surface wave processing part

Methodology Applied
Scientific EffectPressure calculation from wave velocity:

Data Source

PatentEP4342362B1Non-contact type eyeball physical property measurement device
Publication Date: 2026.03.25 QUOVISU LLC
  • EP4342362B1 patent drawingFigure 1
  • EP4342362B1 patent drawingFigure 2
  • EP4342362B1 patent drawingFigure 3~5

AI summary

A non-contact type ocular physical property measuring device 1 of this invention comprises: an excitation part 102 that excites at least one or more excitation points on an eyeball by using an irradiation wave to generate a surface wave on a surface of an eye to be examined; a detection part 103 that detects the surface wave generated by the excitation part 102 at at least one or more detection points, which are different from the excitation points, on the eyeball; a surface wave processing part 208 that analyzes the surface wave detected by the detection part 103; and an ocular physical property calculation part 209 that calculates physical properties of the eyeball based on the analyze result by the surface wave processing part 208. With this configuration, the ocular physical property measuring device 1 according to the present invention can measure an intraocular pressure and so on using surface waves generated on the eyeball surface intentionally by the excitation part 102 without any vibration of the eyeball itself or the cornea itself. As a result, it is possible to measure intraocular pressure, Young's modulus, shear modulus, viscosity, etc. of ocular tissue without the examinee feeling any discomfort.