Inline PAP Muffler Baffle Structure for Acoustic Noise Reduction

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Solution Overview

Problem

Positive airway pressure therapies generate bothersome acoustic noise that interferes with user comfort and sleep, particularly due to the operation of blowers and gas flow through delivery conduits.

Innovation Solution

An inline muffler is positioned between the blower and user interface, featuring a tubular housing with an expansion chamber and inwardly extending baffles to capture and attenuate sound energy associated with the flow of pressurized gas, utilizing various baffle configurations to disrupt and redirect sound waves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a blower is used to generate pressurized gas flow for positive airway pressure therapy, then the required pressure and flow are achieved, but acoustic noise is generated that interferes with user comfort and sleep

Engineering Contradiction:

Improvepressurized gas flow capabilityVSAvoidacoustic noise

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

An inline muffler is introduced as an intermediary component between the blower and the delivery tube. The muffler contains an expansion chamber with inwardly extending baffles that intercept and attenuate acoustic noise from the pressurized gas flow while allowing the gas flow itself to pass through to the user interface

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful acoustic noise is extracted or separated from the useful pressurized gas flow using the muffler's expansion chamber and baffle structure. The baffles intercept sound waves and redirect them, allowing the noise to be dissipated while the therapeutic gas flow continues uninterrupted to the user

Inventive Principle:

Principle #2Taking out (Extraction)

2Stress or pressure

If the blower operates at higher speeds to increase therapy pressure, then the therapeutic effect is improved, but the acoustic noise increases

Engineering Contradiction:

Improvetherapy pressureVSAvoidacoustic noise

Core Design Contradiction:

Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The muffler serves as a pressure-preserving noise-filtering intermediary that allows high-speed blower operation to maintain therapeutic pressure while attenuating the associated acoustic noise through its expansion chamber and baffle structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The muffler converts the harmful acoustic noise generated by high-speed blower operation into a beneficial situation by dissipating the sound energy through the expansion chamber and baffles, allowing the blower to operate at optimal speeds for therapy pressure without transmitting the noise to the user

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 muffler effectively reduces acoustic noise detected at the user interface, enhancing user comfort and sleep quality by minimizing sound propagation through the delivery conduit.

Implementation Method 1

the baffles adapted to capture sound energy associated with the flow of pressurized gas passing through the expansion chamber

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS12576231B2Inline muffler and positive airway pressure therapy apparatus including same

Publication Date: 2026.03.17 SOMNETICS INTERNATIONAL INC

AI summary

An inline muffler for use with a positive airway pressure (PAP) apparatus. The muffler may provide an expansion chamber with baffles that capture acoustic energy using, for instance, a disruptive gas flow path to effectively reduce downstream noise associated with a flow of pressurized gas produced by the PAP apparatus. In some embodiments, the muffler is constructed of two mostly identical halves with baffle segments being integrally formed therewith.