Curved Weld Inflatable Cell for Anti-Bedsore Mattress Alignment

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Solution Overview

Problem

Inflatable anti-decubitus mattresses face challenges in preventing bedsores and accidental falls, particularly due to issues with cell alignment and pressure distribution, which can lead to inadequate relief and increased risk of falls in bedridden individuals with reduced motor skills.

Innovation Solution

The design of an inflatable anti-decubitus mattress cell with a unique envelope structure featuring a curved lower longitudinal weld and oblong vertical welds, allowing for a convex supporting surface that prevents vertical sliding and ensures proper alignment, while also providing a bowl-shaped anti-fall profile to stabilize the user.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the width of the supporting surface of each cell is increased, then the load-bearing capacity is improved, but a tourniquet effect occurs on the bedridden person

Engineering Contradiction:
Improveload-bearing capacityVSAvoidtourniquet effect
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The mattress is divided into multiple independent inflatable cells arranged in columns and rows. Each cell can be independently inflated or deflated, allowing the system to distribute load across multiple segments rather than concentrating it on a single large cell, thereby preventing the tourniquet effect while maintaining adequate load-bearing capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mattress operates in dynamic mode where cells are cyclically inflated and deflated according to a predetermined sequence. This dynamic operation allows cells to alternate between supporting and relieving positions, preventing continuous compression on any single area while maintaining overall load-bearing capability.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the width of the supporting surface of each cell is decreased, then the tourniquet effect is avoided, but the dynamic relief effect is no longer felt by the bedridden person

Engineering Contradiction:
Improvetourniquet effectVSAvoiddynamic relief effect
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

By segmenting the mattress into multiple smaller cells, the system achieves both reduced individual cell width (avoiding tourniquet effect) and maintained dynamic relief effect through coordinated cyclic operation of multiple cells. The collective action of many small cells provides the necessary pressure redistribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mattress employs periodic inflation and deflation cycles of cells in a predetermined sequence. This periodic action ensures that while individual cells are small, their coordinated cyclic operation creates the dynamic relief effect needed for pressure sore prevention.

Inventive Principle:
Principle #19Periodic action

3Device complexity

If circular welding points are used to fix the internal sheet, then the cell structure is simplified, but neighboring cells slide vertically resulting in poor alignment

Engineering Contradiction:
Improvecell structureVSAvoidcell alignment
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

Instead of using circular (point) welds, the invention uses longitudinal linear welds that extend along the length of the cell. This inversion from point to line contact provides continuous alignment constraints, preventing vertical sliding between cells while maintaining structural simplicity.

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

Solution Approach 2:

The welding geometry is changed from circular (0D) to longitudinal linear (1D). This parameter change increases the contact length between the internal sheet and envelope, providing sufficient friction and mechanical interlocking to prevent vertical sliding while maintaining ease of manufacture.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If horizontal oblong welds are used in cells, then the structure is simplified, but positioning defects occur requiring additional support fixation

Engineering Contradiction:
Improveweld structureVSAvoidcell positioning
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The invention inverts the weld orientation from horizontal to longitudinal (vertical). This orientation change allows the weld to span the full height of the cell envelope, providing continuous vertical constraint that prevents positioning defects and eliminates the need for additional support fixation.

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

Solution Approach 2:

The weld is extended from a horizontal dimension to a vertical dimension, utilizing the full height of the cell envelope. This dimensional change transforms the weld from a limited horizontal constraint to a comprehensive vertical constraint, preventing sliding without additional supports.

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

Data Source

PatentEP2500004B1Inflatable cell of an anti-bedsore mattress
Publication Date: 2013.07.10 MULLIEZ THADDEE
  • EP2500004B1 patent drawingFigure 1
  • EP2500004B1 patent drawingFigure 2~3
  • EP2500004B1 patent drawingFigure 4

AI summary

The inflatable cell of the anti-bedsore mattress comprises an inflatable envelope (2), of elongated shape, which has two opposing principal lateral faces (20d, 20e) and a top surface (SP) which in the inflated state of the envelope forms a top load-bearing surface; the two opposing principal lateral faces (20d, 20e) of the cell are welded together on at least three sides of their periphery by means of at least one lower longitudinal weld line (4) and two lateral weld lines (5); said lower longitudinal weld line (4) has a curved profile such that the height H1 at the center of the envelope (2) in the deflated state is less than the height H2 at the ends of the envelope in the deflated state.