Retractable Strap Mechanism for Respiratory Mask Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing patient interface systems for treating sleep disordered breathing are often obtrusive, poorly fitting, uncomfortable, and difficult to use, leading to issues with seal formation and patient compliance, especially when worn for extended periods.
Innovation Solution
A patient interface system featuring a retractable positioning and stabilizing structure with a mechanical retraction mechanism that automatically adjusts straps to fit various head sizes, providing a consistent and comfortable seal without requiring patient actuation, using a combination of retractors and pads to distribute tension evenly and minimize discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional headgear with manual strap adjustment is used, then the mask can be fitted to the patient's face, but the system becomes obtrusive and difficult to use, reducing patient compliance
Solution Approach 1:
The retractor mechanism automatically adjusts and secures the mask to the patient's face without requiring manual intervention. The elastic element continuously pulls the strap to maintain optimal tension, allowing the system to self-regulate and eliminating the need for patient adjustment during use.
Solution Approach 2:
The system transitions from static manual adjustment to dynamic automatic adjustment. The retractor mechanism with elastic element continuously adapts the strap tension based on patient movement and face shape, providing real-time optimization without patient involvement.
2Reliability
If manual strap tightening is allowed, then the mask seal can be adjusted, but the user may over tighten the straps causing discomfort and pain
Solution Approach 1:
The elastic element in the retractor provides continuous feedback-based tension control. As the mask is pulled toward the patient's face, the elastic element automatically regulates the force applied, preventing over-tightening while maintaining sufficient seal pressure. The system self-adjusts based on the resistance encountered.
Solution Approach 2:
The system incorporates pads at the strap contact points with the patient's head before the tightening force is applied. These pads cushion the areas that would otherwise be subjected to concentrated pressure, distributing the force and preventing discomfort or pain from excessive tension.
3Ease of manufacture
If a one-size-fits-all mask design is used, then manufacturing is simplified, but the mask does not fit various head sizes properly
Solution Approach 1:
The retractable positioning structure with elastic element provides dynamic adaptability to different head sizes. The mechanism allows the mask to be pulled to varying degrees based on the patient's head circumference, with the elastic element automatically adjusting the tension to achieve optimal fit across a range of sizes without requiring multiple mask designs.
Solution Approach 2:
The retractor mechanism serves multiple functions: it secures the mask, adjusts for different head sizes, maintains seal pressure, and prevents over-tightening. This single universal mechanism replaces the need for multiple specialized fittings or adjustment systems for different patient populations.
4Reliability
If the mask is secured tightly to ensure seal, then therapeutic efficacy is improved, but the system becomes obtrusive and uncomfortable for extended wear
Solution Approach 1:
Pads are positioned at the strap contact points with the patient's head to cushion areas subjected to tension forces. This distribution of pressure prevents pain and discomfort that would otherwise limit wear duration, allowing the tight seal necessary for therapeutic efficacy to be maintained comfortably over extended periods.
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 effectively seals the patient's airways with reduced discomfort and improved fit, accommodating a wide range of head sizes while maintaining therapeutic efficacy and patient comfort, allowing for 100% of the adult population to be comfortably fitted with optimal pressure for effective therapy.
Implementation Method 1
The retractor may comprise a housing and an elastic element contained within the housing. The elastic element may be configured to urge the patient interface toward the patient's face.
Data Source
Figure 1a
Figure 1b
Figure 1c
AI summary
A patient interface system to treat sleep disordered breathing of a patient with pressurized gas, comprising a patient interface. The patient interface includes a plenum chamber configured to be pressurised above atmospheric pressure in use by the pressurized gas; and a seal-forming structure connected to the plenum chamber and structured to seal against the patient's face around the nose and/or mouth to direct the pressurized gas into the patient's airways during use; and a positioning and stabilising structure configured to hold the seal-forming structure in a sealing position against the patient's face. The positioning and stabilising structure includes at least one strap; at least one cushion formed from a soft, flexible composite material and structured to at least partially conform to the patient's head; and at least one retractor fixedly attached to said at least one cushion. The at least one retractor is connected to the at least one strap and configured to retract the at least one strap without patient actuation to urge the patient interface into the sealing position against the patient's face during use, wherein the at least one strap joins the at least one retractor to the patient interface.