Compact Forehead Thermometer with Infrared Sensor Array

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Solution Overview

Problem

Existing thermometer devices for measuring body core temperature face challenges such as unhygienic methods, accuracy issues with forehead scanning, bulkiness, and impracticality for self-measurements, especially for individuals with medical contraindications or hearing aids, and difficulties in obtaining accurate readings from the temporal artery area.

Innovation Solution

A compact thermometer device with a stationary design that applies directly to the temporal region, using an array of infrared sensors for accurate peak temperature detection, providing audio/vibratory feedback, and analyzing signals to locate the temporal artery, while being easy to use and sanitize, with features like a wireless interface for user profiles and a small, cylindrical shape for easy storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a sweeping thermometer device is used to measure forehead temperature, then the measurement can be performed, but the accuracy is reduced because the device must be spaced from the skin to allow cross movement

Engineering Contradiction:
Improveease of measurementVSAvoidtemperature accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

Instead of moving the device across the forehead to locate the temporal artery, the invention inverts the approach by keeping the device stationary and having the user move their hand or head to bring the temporal artery into contact with the sensor array. This eliminates the spacing requirement and improves measurement accuracy while maintaining ease of operation.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention introduces an intermediary approach where the user's hand or head movement serves as the mediator to position the temporal artery under the stationary sensor array. This allows accurate measurement without requiring the device itself to move or be spaced from the skin.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the device is designed with a large sensing region for accurate temporal artery detection, then measurement accuracy improves, but the device becomes bulkier

Engineering Contradiction:
Improvetemporal artery detection accuracyVSAvoiddevice size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The invention transitions from a traditional linear or planar sensor arrangement to a three-dimensional sensor array configured in a cylindrical or spherical volume. This allows the sensing region to extend in multiple dimensions, providing accurate temporal artery detection while keeping the overall device footprint compact. The sensor array is arranged to detect temperature variations from different angles and depths simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The sensor array is nested within a compact housing structure, with the sensing elements arranged in a space-efficient configuration. The cylindrical or spherical sensor arrangement allows the large sensing region to be contained within a small overall device volume, eliminating the trade-off between sensing area and device size.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Object-affected harmful factors

If a probe cover is provided for ear thermometer hygiene, then sanitation is improved, but the method remains unhygienic and contaminated by ear canal dirt

Engineering Contradiction:
ImprovehygieneVSAvoidmeasurement reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention extracts the measurement function from the problematic ear canal environment and relocates it to the temporal artery area on the forehead. This eliminates contact with the ear canal and its contaminants, providing both hygienic measurement and reliable temperature reading without the need for probe covers or protective barriers.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If the device is designed for stationary application on the temporal region, then usability and measurement reliability improve, but the device must be precisely positioned

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidpositioning ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The device incorporates self-positioning features such as a movable jaw or clamping mechanism that automatically adjusts to fit the user's temporal region. The sensor array is designed to maintain optimal contact with the temporal artery regardless of slight position variations, and the device can detect when proper contact is made, eliminating the need for precise manual positioning while ensuring reliable measurements.

Inventive Principle:
Principle #25Self-service

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 device offers fast, accurate, and user-friendly body core temperature measurements, improved usability, and increased reliability, along with the ability to assess vascular diffusion for conditions like fever or stress, all while being compact and easy to handle.

Implementation Method 1

an array of at least N infra-red sensors, with N greater than 8

Methodology Applied
Scientific EffectInfrared radiation detection: Infrared Radiation

Implementation Method 2

the infra-red sensors are thermopiles

Methodology Applied
Scientific EffectThermopile effect: Thermopile

Data Source

PatentEP3397930B1Compact forehead thermometer
Publication Date: 2021.01.27 WITHINGS SAS
  • EP3397930B1 patent drawingFigure 1~4
  • EP3397930B1 patent drawingFigure 5~6
  • EP3397930B1 patent drawingFigure 7~8C

AI summary

A thermometer device (10) for temporal artery area measurement, configured to be used in a skin-touching stationary position, comprising an elongated body (1) and a front portion (4) having an end border (6) arranged on a sensing plane (P), an array of N infra-red sensors (2), with N greater than 8, a sensing region (SR) extending in the sensing plane over an area denoted SRA, at a distance denoted LF from a plane P2 containing the infra-red sensors, the sensing region being encompassed within the border of the front end, an optical lens (3), interposed between the infra-red sensors and the sensing region, to deviate light rays, wherein LF2 < K x SRA, with K =3.