Absorbent Article Wetness Sensor With Variable Strip Spacing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current absorbent articles lack effective monitoring systems to indicate when they become wet due to incontinence, making it difficult for caregivers to determine when they need to be changed, despite existing devices being inadequate in this regard.

Innovation Solution

A sensor system is integrated into absorbent articles, featuring metal strips with varying spacings that change resistance when wet, connected to a comparator circuit to provide a measurable output, and an indicator device that attaches to the article to signal wetness and differentiate between different article sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a wetness sensor system is integrated into absorbent articles, then monitoring capability is improved, but device complexity increases

Engineering Contradiction:
Improvemonitoring capabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex electronic sensing systems with a simple electrical resistance measurement system. Metal strips embedded in the absorbent article change electrical resistance when wet, which can be detected by a simple comparator circuit, eliminating the need for complex sensors and electronics while providing reliable wetness monitoring

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

Solution Approach 2:

The absorbent article itself serves as the sensor through its material properties. The metal strips embedded in the absorbent core automatically change resistance when exposed to body fluids, requiring no external power source or complex electronics - the article's material composition provides the sensing function

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If metal strips with varying spacings are used, then size differentiation is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvesize differentiationVSAvoidspacing precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies different metal strip spacing configurations to different absorbent article sizes. Each size category (e.g., small, medium, large) has metal strips spaced at specific distances that are characteristic of that size, allowing the sensor to identify the article size based on the spacing pattern rather than requiring complex measurement systems

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses changes in the physical parameter of metal strip spacing to encode size information. By varying the distance between metal strips as a discrete parameter during manufacturing, different size categories are created, and this parameter can be easily measured during use to identify the article size without requiring complex sensors

Inventive Principle:
Principle #35Parameter changes

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 sensor system effectively monitors wetness and provides a clear indication to caregivers when the article needs to be changed, ensuring timely replacement and improving care for users by providing accurate size verification and comfort through reduced pressure points.

Implementation Method 1

metal strips with varying spacings that change resistance when wet

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP3471677B1Sensor for absorbent article
Publication Date: 2023.01.11 MEDLINE INDUSTRIES
  • EP3471677B1 patent drawingFigure 1
  • EP3471677B1 patent drawingFigure 2
  • EP3471677B1 patent drawingFigure 3~4

AI summary

A sensor for monitoring wetness in a diaper or other absorbent article includes a housing that attaches to the absorbent article. The sensor may include inner and outer housing portions that capture an edge of the absorbent article between the housings. The sensor may include contacts that electrically connect with a pair of contact strips embedded in the absorbent article. The distance between the embedded strips may vary depending on the size of the absorbent article. The sensor may include multiple pairs of contacts that are spaced apart to match the distance between the contact strips for the variously sized absorbent articles. In this way, depending on the pair of contacts connected to the contact strips, the sensor may indicate the size of the absorbent article.