Smart Contact Lens With Concentric LCD Rings for Adaptive Light Detection

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Solution Overview

Problem

Existing smart contact lenses struggle to detect a ratiometric change in light intensity across varying lighting conditions, such as dim indoor and bright outdoor environments, necessitating a high dynamic range for accurate detection.

Innovation Solution

A smart contact lens with concentric LCD rings and a circuit that includes a light sensor, operational amplifier, feedback loop, high-pass filter, and comparison element to detect ratiometric changes in light intensity, allowing for controlled light attenuation and re-polarization based on ambient light levels, with a low power consumption design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the contact lens uses a photodetector to detect light changes, then it can detect blinking events, but it cannot accurately detect ratiometric changes across varying lighting conditions (dim indoor to bright outdoor)

Engineering Contradiction:
Improvelight intensity detection accuracyVSAvoidadaptability to varying lighting conditions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements a feedback mechanism where the photodetector continuously monitors ambient light intensity and feeds this information back to the controller. The controller adjusts the LCD ring attenuation levels based on this feedback, enabling the system to adapt to varying lighting conditions while maintaining accurate ratiometric detection capability across different environmental lighting levels.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs dynamic adjustment of the LCD ring attenuation levels based on real-time light intensity detection. The system transitions from static fixed attenuation to dynamic variable attenuation, allowing the contact lens to adapt its light control characteristics according to ambient lighting conditions, thereby achieving both high measurement precision and versatility.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the LCD rings are re-polarized frequently to maintain contrast, then image quality is preserved, but visual flicker is introduced to the user

Engineering Contradiction:
ImproveLCD contrast maintenanceVSAvoidvisual flicker
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements self-service by using the photodetector to automatically detect when the user's eye is open or closed based on ambient light intensity changes. The controller then autonomously determines the optimal timing for re-polarization, re-polarizing the LCD rings only when necessary (when the eye is closed) and avoiding unnecessary re-polarization when the eye is open, thereby maintaining contrast without introducing visual flicker.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from the photodetector to monitor eye state and control re-polarization timing. The continuous light intensity measurement provides feedback that enables the controller to synchronize re-polarization operations with the user's blinking cycle, ensuring contrast maintenance occurs only when visually imperceptible.

Inventive Principle:
Principle #23Feedback

3Illumination intensity

If the contact lens operates in bright outdoor lighting conditions, then it can provide sufficient light attenuation, but it cannot detect subtle light changes in dim indoor environments

Engineering Contradiction:
Improvelight attenuation capabilityVSAvoidlight change detection sensitivity
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by adjusting the attenuation level of the LCD rings dynamically based on detected light intensity. In bright outdoor conditions, the system increases attenuation to provide sufficient light control, while in dim indoor environments, it reduces attenuation to maintain detection sensitivity. This dynamic parameter adjustment enables the system to handle both high and low light conditions effectively.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system transitions from static fixed attenuation to dynamic variable attenuation that adapts to ambient lighting conditions. The photodetector continuously monitors light intensity and triggers appropriate attenuation levels, enabling the contact lens to maintain both strong light blocking capability in bright conditions and subtle detection sensitivity in dim conditions through dynamic operation.

Inventive Principle:
Principle #15Dynamics

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

The solution enables the contact lens to mimic the iris function, providing effective light control and reducing visual flicker by re-polarizing rings during blinking, while maintaining a high signal-to-noise ratio and dynamic range.

Implementation Method 1

a light sensor configured to induce a photocurrent through it as a function of an intensity of an incident light

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

one or more, preferably concentric, rings of a liquid crystal display, LCD, type, each ring being operable between a state having a lower attenuation of light and a state having a higher attenuation of light

Methodology Applied
Scientific EffectLiquid Crystal Effect: Liquid Crystals

Data Source

PatentEP3973352B1Smart contact lens with ratiometric light change detection
Publication Date: 2025.08.20 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP3973352B1 patent drawingFigure 1a~1b
  • EP3973352B1 patent drawingFigure 2
  • EP3973352B1 patent drawingFigure 3~4

AI summary

A smart contact lens (400) for detecting a ratiometric change in an incident light (126) intensity is provided, including one or more, preferably concentric, rings (410-1, 410-2, …, 410-N) of a liquid crystal display, LCD, type, each ring being operable between a state having a lower attenuation of light and a state having a higher attenuation of light; a circuit (420, 100, 101) for detecting a ratiometric change in an incident light intensity; and a controller (430) configured to operate the one or more rings based on an intensity of an incident light and to, as a response to the circuit (420, 100, 10 101) detecting a ratiometric change in the intensity of the incident light from a higher intensity state to a lower intensity state indicating that at least a beginning of a blinking of an eye of a user has occurred, initiate a re-polarization of the one or more rings. A method of operating the smart contact lens and various uses of the circuit are also provided.