Fluid-Filled CPAP Cushion for Seal Reliability and Skin Comfort

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Patients undergoing CPAP therapy for sleep disordered breathing face issues such as skin irritation, pressure sores, discomfort, and mask leaks due to prolonged mask use, which can lead to ineffective treatment and reduced sleep quality.

Innovation Solution

A patient interface with a cushion that can change properties like temperature and pressure, using fluid-filled cavities with a micro pump and heating/cooling elements to stimulate blood circulation, reduce pressure points, and release skin care substances, thereby improving comfort and therapy efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mask cushion applies pressure to seal against the patient's face, then the seal reliability is improved, but skin irritation and pressure sores occur

Engineering Contradiction:
Improveseal reliabilityVSAvoidskin irritation and pressure sores
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The cushion incorporates a fluid-filled chamber that can dynamically adjust its pressure and volume. The fluid (gas or liquid) allows the cushion to adapt its sealing force distribution, maintaining reliable sealing while reducing concentrated pressure points that cause skin irritation and pressure sores.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cushion's physical parameters (pressure, volume, density) are made changeable through the fluid-filled chamber. By adjusting the fluid pressure and volume, the cushion can modify its contact pressure distribution on the patient's face, achieving effective sealing while minimizing harmful pressure concentrations.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If headgear straps are tightened to stop mask leaks, then the seal reliability is improved, but discomfort and pressure sores increase

Engineering Contradiction:
Improveseal reliabilityVSAvoiddiscomfort and pressure sores
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The sealing function is extracted from the headgear strap system and transferred to the cushion's fluid-filled chamber. This allows the headgear straps to be loosened, reducing discomfort and pressure sores, while the cushion independently maintains the necessary seal through its adjustable fluid pressure mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cushion dynamically compensates for leaks caused by patient movement by adjusting fluid pressure in real-time, eliminating the need for continuous tight headgear straps and thereby reducing discomfort and skin damage.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the mask is worn for prolonged periods to ensure full night treatment, then therapy effectiveness is improved, but skin circulation is impeded causing sores

Engineering Contradiction:
Improvetherapy effectivenessVSAvoidskin circulation impairment
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The fluid-filled chamber can be programmed to periodically adjust its pressure and volume during therapy. This periodic adjustment creates temporary relief from pressure on specific skin areas, restoring blood circulation while maintaining overall seal integrity and continuing effective therapy throughout the night.

Inventive Principle:
Principle #19Periodic action

4Reliability

If the cushion is made rigid to maintain shape and seal, then seal reliability is improved, but comfort and ability to relax are reduced

Engineering Contradiction:
Improveseal reliabilityVSAvoidcomfort and ability to relax
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cushion uses a flexible membrane or thin-walled structure containing the fluid-filled chamber. This flexible shell maintains the necessary shape for sealing while conforming to the patient's face contours, providing comfort and allowing the patient to relax without compromising seal reliability.

Inventive Principle:
Principle #30Flexible shells and thin films

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 dynamic properties of the cushion reduce pressure sores, enhance comfort, and prevent mask leaks, ensuring effective treatment by stimulating blood circulation and maintaining a comfortable seal during extended use.

Implementation Method 1

a heating element in functional relationship with the cushion and operable to increase the temperature of the fluid in the cushion cavity

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a cooling element in functional relationship with the cushion and operable to decrease the temperature of the fluid in the cushion cavity

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 3

a micro pump in functional relationship with the cushion and operable to increase the pressure of the fluid in the cushion cavity

Methodology Applied
Scientific EffectPumping: Pump

Data Source

PatentEP3906956B1A patient interface
Publication Date: 2023.10.25 RESMED PTY LTD
  • EP3906956B1 patent drawingFigure 1
  • EP3906956B1 patent drawingFigure 2
  • EP3906956B1 patent drawingFigure 3~6

AI summary

A patient interface for providing breathable gas to a patient, comprising a face engaging cushion, the cushion comprising an internal cavity that is adapted to contain fluid and a control means being capable of communicating with the fluid for inciting change to at least one property of the fluid, wherein the at least one property can be actively changed in response to a therapeutic condition of the patient.