Patient Interface Exhalation System With Multi-Path Noise Reduction

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Solution Overview

Problem

Existing patient interfaces during ventilation or respiratory support result in unpleasant and disturbing noise due to exhaled breathing gas escaping into the environment, affecting both the user and bed partners, and there is a need for a quieter and more comfortable solution.

Innovation Solution

An exhalation system for patient interfaces featuring at least two walls with distinct flow paths and groove arrangements that direct exhaled respiratory gas away from the environment, reducing noise and pressure, utilizing a ball joint for connection to a ventilator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If exhaled breathing gas is directed directly from the patient interface into the environment, then CO2 accumulation is prevented, but noise is generated that disturbs the user and bed partner

Engineering Contradiction:
Improveprevention of CO2 accumulationVSAvoidnoise disturbance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The exhalation system divides the single exhalation flow into multiple parallel flow paths (first flow path between walls, second flow path enclosed by second wall, and branch between second and third walls). This segmentation allows the exhaled gas to be distributed across multiple channels, reducing the noise intensity of each individual path while maintaining effective CO2 removal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a multi-dimensional flow distribution system with walls arranged in spatial relationships (first wall, second wall, third wall) creating three-dimensional flow paths. The groove arrangements in the walls further subdivide the flow into multiple directional channels, transforming a single-direction noisy flow into multi-directional distributed flow, thereby reducing noise propagation.

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

2Object-affected harmful factors

If multiple flow paths are introduced to reduce noise, then noise disturbance is minimized, but device complexity increases

Engineering Contradiction:
Improvenoise disturbanceVSAvoidstructure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The walls serve multiple functions simultaneously: they define the flow paths, create the groove arrangements for flow subdivision, provide structural support, and guide the exhaled gas distribution. This multi-functionality reduces the need for additional separate noise-reducing components, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The flow paths are nested within the wall structures, with grooves embedded in the walls creating channels. The second flow path is enclosed by the second wall, and the branch runs between the second and third walls. This nested arrangement integrates multiple flow paths within a compact structure, avoiding the need for separate external noise-reduction devices.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 exhalation system effectively reduces noise and pressure by directing exhaled gas away from the environment, providing a quieter and more comfortable ventilation experience for users and minimizing disturbance to bed partners.

Implementation Method 1

the first flow path runs at least partially between the first wall and the second wall and the first flow path is designed to at least temporarily reduce respiratory gas pressure

Methodology Applied
Scientific EffectPressure reduction through flow: Pressure Drop

Implementation Method 2

the second flow path is at least partially enclosed by the second wall and the second flow path is at least partially designed to at least temporarily flow respiratory gas into the interior space of the patient interface

Methodology Applied
Scientific EffectGas flow through enclosed channel:

Implementation Method 3

At least four groove arrangements are arranged in at least one of the walls, each groove arrangement comprising at least two grooves and the grooves forming channels together with the other wall

Methodology Applied
Scientific EffectGas conduction through grooves:

Data Source

PatentEP4070843B1Exhalation system and ball joint for patient interface
Publication Date: 2025.07.16 LOWENSTEIN MEDICAL TECH SA
  • EP4070843B1 patent drawingFigure 1
  • EP4070843B1 patent drawingFigure 2
  • EP4070843B1 patent drawingFigure 3

AI summary

The invention relates to an exhalation system (3) for a patient interface (1), comprising at least two walls (301, 302), wherein the walls are arranged at least partially adjacent to one another. The exhalation system is characterized by having at least two flow paths (S1, S2) for the flow of respiratory gas from an interior space (101) of the patient interface, wherein the first flow path (S1) runs at least partially between the first wall (301) and the second wall (302) and is designed for the at least temporary reduction of respiratory gas pressure, and wherein the second flow path (S2) is at least partially enclosed by the second wall and is designed for the at least temporary flow of respiratory gas into the interior space of the patient interface.