Contact Lens Pupil Sensor Through Closed Eyelid

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Solution Overview

Problem

Current pupil monitoring systems are limited by their inability to continuously monitor pupil size over extended periods without causing eye discomfort or requiring artificial tears, and they are not suitable for unconscious subjects as they necessitate keeping the eye open.

Innovation Solution

A sensor is placed between the eyeball and the eyelid, using photoelectric detectors to measure pupil size through the eyelid, allowing for continuous monitoring with the eyelids closed, and includes a signal processing unit and wireless transmission for data and power, ensuring comfort and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the eye is kept open for pupil measurement, then pupil size can be measured, but the eye dries out and monitoring can only be performed for short periods

Engineering Contradiction:
Improvemonitoring durationVSAvoideye drying
Core Design Contradiction:
Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a contact lens as an intermediary device between the eye and the external environment. This contact lens integrates illumination sources and photodetectors, allowing pupil measurement to be performed while the eye remains closed or partially closed, thereby preventing eye drying while maintaining measurement capability over extended periods

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical requirement of keeping the eye open with an optical system integrated into a contact lens. The illumination LEDs and photodetectors within the contact lens create an optical measurement path that works through the closed eyelid, eliminating the need to mechanically keep the eye open

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

2Ease of operation

If the eye is kept open for pupil monitoring, then continuous measurement is possible, but unconscious subjects cannot be monitored and artificial tears are required

Engineering Contradiction:
Improvemonitoring applicabilityVSAvoidartificial tear supply system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The contact lens device serves multiple functions: it illuminates the pupil, detects pupil size, and allows monitoring while the eye is closed. This multi-functional design enables the system to monitor both conscious and unconscious subjects without requiring artificial tears or special positioning, greatly expanding its applicability

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

Solution Approach 2:

The contact lens acts as an intermediary that enables pupil measurement through the closed eyelid. This eliminates the requirement for the eye to be open, making the system suitable for unconscious subjects and removing the need for artificial tear supplementation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If a transparent body adhering to the eye is used with LEDs and photodiodes, then pupil size can be measured, but the eye must remain open and artificial tears may be necessary

Engineering Contradiction:
Improvepupil size measurementVSAvoideye discomfort
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent merges the illumination function and detection function into a single integrated contact lens unit. The LEDs and photodetectors are embedded within the contact lens structure, allowing both functions to work together while the eye is closed, maintaining measurement precision without causing discomfort

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contact lens serves as an intermediary that enables precise pupil measurement while the eye remains closed. This intermediary structure protects the eye from direct light exposure and mechanical stress, eliminating the need to keep the eye open while maintaining measurement accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

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 prolonged, safe, and comfortable monitoring of pupil size variations, suitable for both conscious and unconscious subjects, without the need for constant eye openness or artificial tears.

Implementation Method 1

The sensor comprises photoelectric detectors - or photoreceptors -, in particular detectors sensitive to infrared radiation, which are arranged to 'observe' the pupil, that is to say to be sensitive to the light reflected by the part of the iris surrounding the pupil.

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP2609852B1Method and apparatus for monitoring the pupil
Publication Date: 2014.09.10 IDMED
  • EP2609852B1 patent drawingFigure 1
  • EP2609852B1 patent drawingFigure 2~3
  • EP2609852B1 patent drawingFigure 4~5

AI summary

The sensor (23) has a proximal lens (40) comprising a proximal concave face resting on a cornea/sclera and convex distal face. A photo receiver i.e. matrix imager (230), faces the distal face to observe a pupil. A cable is connected to the photo receiver and extended with respect to the lens in an extension of the lens. The cable is arranged to transmit signals from the photo receiver through an upper eyelid (28) and lower eyelid. A distal lens (43) covers the photo receiver and a portion of the cable. A convex distal face of the distal lens is adapted to be in contact with the closed eyelids. Independent claims are also included for the following: (1) a device for monitoring a pupil of an eye of a subject (2) a method for monitoring a pupil of a subject.