Helmet Edge Perspiration Sensing With Dual Thermo-Hygro Airflow

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Solution Overview

Problem

Existing perspiration amount measuring devices that utilize helmets with fans are limited in their applicability to specific types of helmets, and there is a need for a device that can accurately measure head perspiration without a fan, while being compact, lightweight, and power-efficient, suitable for general use.

Innovation Solution

A perspiration amount measuring device that is mountable on the edge of a helmet, utilizing a fan with blades to direct air flow through an air path, with thermo-hygro sensors to measure external and internal air humidity and temperature, allowing for accurate head perspiration measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a fan is used to force air movement through the helmet for perspiration measurement, then measurement accuracy is improved, but device complexity and power consumption increase

Engineering Contradiction:
Improveperspiration measurement accuracyVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential measurement function from the complex fan-based system by removing the fan component entirely. Instead of forcing air movement, the invention uses natural air flow within the helmet to transport perspiration vapor to the sensors, achieving accurate measurement through a simplified structure with no moving parts.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system utilizes natural air flow and convection currents that occur automatically within the helmet during wear to move perspiration vapor to the measurement location. This self-service approach eliminates the need for external power sources or mechanical components, achieving both measurement accuracy and device simplicity.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If a fan is installed in the helmet for air flow control, then perspiration measurement capability is improved, but device weight increases

Engineering Contradiction:
Improvehead perspiration measurement accuracyVSAvoidhelmet device weight
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The invention removes the fan component entirely from the helmet system, extracting only the essential measurement function. This elimination of heavy mechanical parts significantly reduces device weight while maintaining perspiration measurement capability through passive sensor detection of natural air flow.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a fan is used to control air flow in the helmet, then measurement reliability is improved, but power consumption increases

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

Solution Approach 1:

The system harnesses natural air flow and body heat-induced convection that occur automatically when the helmet is worn to transport perspiration vapor to the sensors. This self-service mechanism requires no external power source, achieving reliable measurement while consuming zero electrical energy for air movement.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If a large-sized facility is used to measure whole body perspiration, then measurement accuracy is improved, but adaptability to construction sites is reduced

Engineering Contradiction:
Improvewhole body perspiration measurement accuracyVSAvoidsuitability for construction site
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The invention segments the measurement approach by using head perspiration measurement as a representative indicator of whole body perspiration. This segmentation allows the use of a compact wearable device at construction sites while maintaining measurement validity through the established correlation between head and whole body perspiration rates.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses the head as a representative sample or 'copy' of the whole body perspiration process. By measuring perspiration at the head location with a wearable device, the system captures a proportional indication of overall perspiration that can be scaled to estimate whole body values, enabling portable deployment without sacrificing measurement validity.

Inventive Principle:
Principle #26Copying

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 can accurately measure head perspiration amounts and estimate whole body perspiration, suitable for various helmets, with characteristics suitable for wearable use, including compact size, low weight, and power efficiency.

Implementation Method 1

a fan that includes a plurality of blades; and a fan case that houses the plurality of blades therein and is provided with a suction port and a discharge port, the plurality of blades being rotatable about a rotation axis so as to suck the inside air in the air flow path from the suction port and to discharge the inside air to an outside from the discharge port

Methodology Applied
Scientific EffectFan: Fan

Implementation Method 2

a first thermo-hygro sensor that is disposed at a place opened to an external field, and measures a temperature and a relative humidity of outside air that is taken in from a place on a side opposite to the wearer as viewed from the air flow path

Methodology Applied
Scientific EffectThermo-hygro sensing:

Implementation Method 3

a second thermo-hygro sensor that is disposed in a flow of the inside air generated due to an operation of the fan, and measures a temperature and a relative humidity of the inside air

Methodology Applied
Scientific EffectThermo-hygro sensing:

Data Source

PatentEP4678052A1Perspiration amount measurement device and perspiration amount measurement system
Publication Date: 2026.01.14 CANAL WATER CO LTD
  • EP4678052A1 patent drawingFigure 1
  • EP4678052A1 patent drawingFigure 2
  • EP4678052A1 patent drawingFigure 3

AI summary

A perspiration amount measuring device 1 is mountable on an edge portion 102 of a helmet 100 and measures a perspiration amount from a head H. The perspiration amount measuring device 1 includes: an air flow path 100 through which inside air IA flows; a first thermo-hygro sensor 20 that is disposed at a place opened to an external field, and measures a temperature and a relative humidity of outside air OA that is taken in from a place on a side opposite to a wearer as viewed from the air flow path; a fan 30 that sucks the inside air IA and discharges the inside air IA to the outside; a second thermo-hygro sensor 40 that is disposed in a flow of the inside air IA generated due to an operation of the fan 30, and measures a temperature and a relative humidity of the inside air IA. The fan 30 discharges the inside air IA in a direction that intersects with a rotation axis AX about which a blade 33 rotates. The perspiration amount measuring device 1 can be popularly mounted on also a helmet for general use that is not equipped with a fan, and can measure a head perspiration amount more accurately compared to the prior art while having characteristics suitable for wearing on the head.