Waisted Ostomy Appliance Cavity Volume Sagging

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Solution Overview

Problem

Existing ostomy appliances lack enhanced usability in terms of ease of use and discretion, leading to reduced comfort and increased environmental waste due to frequent replacements.

Innovation Solution

Designing an ostomy appliance with a larger cavity volume, a foldable drain, and a seamless transition between sections to minimize sagging and distortion, along with a reliable drainage system for hygienic reuse, thereby increasing the duration of use and reducing waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the cavity volume is increased to extend the period of use, then the duration of action is improved, but the device complexity increases due to larger size and potential sagging issues

Engineering Contradiction:
Improveperiod of useVSAvoiddevice complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The appliance is divided into multiple sections (upper section, waisted section, lower section) with distinct functions. The waisted section acts as a separate structural element that provides support and prevents sagging, while the upper and lower sections handle different aspects of effluent management. This segmentation allows each part to be optimized independently, maintaining structural integrity while increasing overall cavity volume.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a waisted section that adds a dimensional intermediate structure between the upper and lower sections. This intermediate dimension provides structural support and prevents the appliance from sagging, enabling the cavity to accommodate larger volumes without compromising structural integrity or increasing apparent complexity.

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

2Loss of time

If the cavity volume is increased to reduce frequency of replacement, then the loss of time is reduced, but the manufacturing precision requirements increase to maintain seamless transitions and prevent distortion

Engineering Contradiction:
Improvefrequency of replacementVSAvoidmanufacturing precision
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

By segmenting the appliance into distinct sections with clear join lines, the patent simplifies the manufacturing process. Each section can be manufactured separately with standard precision requirements, and the join lines are designed to accommodate minor variations, reducing the overall manufacturing precision requirements while maintaining seamless appearance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different structural characteristics to different sections. The waisted section has specific structural properties optimized for support, while the upper and lower sections have properties optimized for effluent containment. This local optimization allows each section to be manufactured with appropriate precision for its specific function, reducing overall manufacturing complexity.

Inventive Principle:
Principle #3Local quality

3Reliability

If the appliance is designed for hygienic reuse with reliable drainage, then the reliability is improved, but the device complexity increases due to additional drainage components

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lower section serves multiple functions: it provides structural support, contains the drainage system, and facilitates hygienic reuse. By making this section multi-functional, the patent reduces the need for separate dedicated components for each function, thereby improving reliability without proportionally increasing device complexity.

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

Solution Approach 2:

The drainage system is designed to be self-regulating, using the natural flow of effluent and gravity to maintain proper drainage without requiring complex active control mechanisms. The structure itself facilitates drainage through its design, reducing the need for additional active components and maintaining simplicity while ensuring reliable hygienic reuse.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4497421B1Ostomy appliance
Publication Date: 2026.01.14 CONVATEC LTD
  • EP4497421B1 patent drawingFigure 1
  • EP4497421B1 patent drawingFigure 2
  • EP4497421B1 patent drawingFigure 3

AI summary

An ostomy appliance comprising an inner wall and an outer wall that define a cavity for containing a stomal output, the ostomy appliance having an upper section, a lower section and a waisted section that is located between the upper section and the lower section. The upper section has a maximum width (A) that is greater than a maximum width (B) of the lower section and the waisted section has a minimum width (C) that is less than the maximum width (B) of the lower section. The waisted section has a left-hand edge that is smoothly rounded and a right-hand edge that is smoothly rounded, and both the left-hand edge and the right-hand edge smoothly blend, respectively, into left-hand edges and right-hand edges of the upper section and the lower section.