CPAP Cushion Seal Structure With Varying Thickness for Comfort

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Solution Overview

Problem

Existing respiratory treatment systems, such as CPAP therapy, face challenges with patient compliance due to discomfort, poor fit, and difficulty in use, leading to ineffective treatment of conditions like obstructive sleep apnea and other respiratory disorders.

Innovation Solution

A patient interface with a seal-forming structure having varying thickness and a positioning and stabilizing mechanism that maintains a seal during side and supine sleeping positions, combined with a gas washout vent to minimize CO2 rebreathing, enhancing comfort and efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a seal-forming structure with uniform thickness is used, then the manufacturing process is simple, but the seal effectiveness and patient comfort are insufficient

Engineering Contradiction:
Improveseal effectivenessVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The sealing structure employs varying wall thickness across different regions to optimize local performance. Thinner sections provide flexibility for conforming to facial contours and achieving effective seals, while thicker sections provide structural support and durability. This non-uniform thickness distribution resolves the contradiction by enhancing seal effectiveness through localized material property optimization without requiring complex manufacturing processes.

Inventive Principle:
Principle #3Local quality

2Reliability

If the patient interface is secured tightly to maintain seal, then the seal effectiveness improves, but the patient comfort and compliance deteriorate

Engineering Contradiction:
Improveseal effectivenessVSAvoidpatient comfort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The interface structure distributes sealing force through strategically positioned thicker wall sections that provide structural support, while thinner sections allow for gentle conformity to facial features. This localized variation in material distribution enables the interface to maintain reliable seals without requiring excessive overall tightening, thereby preserving patient comfort and compliance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sealing structure incorporates flexible regions with varying thickness that can dynamically adapt to different sleeping positions and facial movements. The thinner sections provide enhanced flexibility allowing the interface to maintain seal effectiveness during patient movement without requiring tight fixation, thus improving comfort while preserving reliability.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the sealing structure is made more flexible to improve comfort, then the patient compliance improves, but the ability to maintain therapeutic pressure deteriorates

Engineering Contradiction:
Improvepatient comfortVSAvoidtherapeutic pressure maintenance
Core Design Contradiction:
Ease of operationVSStress or pressure

Solution Approach 1:

The structure combines thinner wall sections for flexibility and comfort with strategically positioned thicker reinforcement sections that maintain structural integrity and pressure containment. This localized thickness variation allows the interface to be flexible where needed for comfort while maintaining sufficient rigidity in critical areas to preserve therapeutic pressure, resolving the contradiction between comfort and pressure maintenance.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4464385B1Patient interface with a seal-forming structure having varying thickness
Publication Date: 2026.04.01 RESMED PTY LTD
  • EP4464385B1 patent drawingFigure 1A
  • EP4464385B1 patent drawingFigure 1B
  • EP4464385B1 patent drawingFigure 1C

AI summary

The present invention relates to a cushion assembly for a patient interface comprising: an elastomeric seal-forming portion including a membrane with an inner boundary, wherein the elastomeric seal-forming portion comprises: a dome-shaped superior region, a saddle-shaped inferior region, a first support region extending from the saddle-shaped inferior region to the dome-shaped superior region, and an attachment structure configured to prevent the inner boundary of the membrane from being blown outwards away from the plenum chamber due to pressurization within the plenum chamber, wherein the attachment structure comprises a first tie extending between a first interior surface region of the cushion assembly and a second interior surface region of the cushion assembly.