Ostomy Electrode Layout for Differentiating Output and Sweat

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Solution Overview

Problem

Existing ostomy appliances lack effective means to reliably sense the presence and nature of liquid output, such as stomal output versus sweat, and to provide timely warnings of potential adhesive failure and leakage risks.

Innovation Solution

An ostomy system with a sensor assembly comprising three electrodes arranged at different radial distances from a stomal opening, a monitor device to determine electrical resistance values, and a method to differentiate between stomal output and sweat based on absolute differences and deviations from initial baselines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single electrode or simple sensor is used, then the device complexity is reduced, but the measurement precision and ability to differentiate liquid types deteriorates

Engineering Contradiction:
Improvesensor structureVSAvoidliquid differentiation capability
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The sensor assembly is segmented into multiple electrodes (first electrode, second electrode, third electrode) arranged at different radial distances from the stomal opening. Each electrode pair forms an independent sensor that can detect liquid presence and propagation direction, enabling precise liquid differentiation without excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the sensor assembly are assigned different functions: the first electrode pair detects liquid near the stomal opening, while the second electrode pair detects liquid at a greater radial distance. This local differentiation enables the system to distinguish between stomal output and external liquid based on spatial location

Inventive Principle:
Principle #3Local quality

2Measurement precision

If multiple sensors are added to improve liquid detection accuracy, then the measurement precision improves, but the device complexity increases

Engineering Contradiction:
Improveliquid detection accuracyVSAvoidsensor assembly structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor assembly uses a universal electrode arrangement where the same three electrodes serve multiple functions: detecting liquid presence, determining liquid propagation direction, and identifying liquid source. This multi-functionality achieves high measurement precision without proportionally increasing device complexity

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

3Reliability

If real-time monitoring is implemented, then the reliability of adhesive failure detection improves, but the use of energy increases

Engineering Contradiction:
Improveadhesive failure detectionVSAvoidmonitor device energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The monitor device continuously monitors the electrical resistance of the sensor assembly to detect adhesive failure, providing reliable real-time detection. The continuous monitoring enables timely warnings while the system is designed to operate efficiently with appropriate energy management

Inventive Principle:
Principle #20Continuity of useful action

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 system accurately detects and differentiates between stomal output and sweat, providing timely warnings of adhesive failure and leakage risks, optimizing ostomy appliance use and reducing skin damage.

Implementation Method 1

resistance of an adhesive layer may be measured across a first and a second electrode

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP4312909B1Liquid sensing in ostomy appliance
Publication Date: 2026.02.04 COLOPLAST AS
  • EP4312909B1 patent drawingFigure 1
  • EP4312909B1 patent drawingFigure 2A~2B
  • EP4312909B1 patent drawingFigure 3A~3B

AI summary

An ostomy system comprising a monitor device and an ostomy appliance is disclosed, the ostomy appliance comprising a sensor assembly comprising three or more electrodes including a first, second and third electrode. The first electrode and the second electrode form a primary sensor, and the first electrode and the third electrode form a secondary sensor. The monitor device is configured to determine a first value of an electrical quantity of the primary sensor, to determine a second value of the electrical quantity of the secondary sensor, and to determine an operating state of the ostomy appliance based on at least the absolute difference between the first value and the second value. Also disclosed is a corresponding method and a monitor device.