Expiratory Valve Outlet Geometry for Stable Low-Noise Exhalation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional expiratory valves in ventilation devices often produce unpleasant noise and can cause auto trigger or auto cycle malfunctions due to oscillating pressure fluctuations, leading to premature initiation of inspiration phases and potential danger for mechanically ventilated patients.
Innovation Solution
The expiratory valve features a fluid flow path with a cross-sectional area that expands towards the outlet, optimized with a cup-shaped valve plenum and a valve bottom design that reduces turbulence, along with reinforcing ribs to minimize retroactive pressure effects and enhance sensitivity to expiration phase changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional expiratory valve design is used, then the valve can discharge exhaled air, but it generates unpleasant noise and causes oscillating pressure fluctuations
Solution Approach 1:
The patent applies curvature by designing the fluid flow path with a continuously expanding cross-sectional area from inlet to outlet, eliminating sharp angles and abrupt transitions. The expiratory valve body features a smooth, curved flow path that guides exhaled air gradually, preventing turbulence and the associated noise and pressure fluctuations while maintaining effective discharge function.
2Device complexity
If the cross-sectional area of the fluid flow path is constant, then the valve structure is simple, but turbulence and retroactive pressure effects increase
Solution Approach 1:
Instead of a constant cross-sectional area, the patent implements a continuously expanding cross-sectional area from inlet to outlet with smooth curved transitions. This geometric modification increases device complexity slightly but dramatically reduces turbulence and retroactive pressure effects by eliminating flow separation and abrupt pressure changes.
Solution Approach 2:
The patent changes the geometric parameter of the fluid flow path cross-sectional area from constant to continuously expanding. This parameter change optimizes the flow characteristics, reducing turbulence and retroactive pressure effects while maintaining structural feasibility and manufacturing capability.
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
This design significantly reduces noise generation and the occurrence of auto trigger malfunctions, ensuring more reliable and sensitive control of exhaled air flow, thereby improving patient safety and ventilation device performance.
Implementation Method 1
When a positive pressure with respect to this pressure is applied to the valve during an expiration phase from the side of the patient, the expiratory valve is to open and permit discharge of the exhaled air to the environment
Data Source
AI summary
An expiratory valve (10) of a ventilation device (100), including a valve body (12) having a fluid inlet (14) and a fluid outlet (16) for breathing air of a patient formed therein the valve body (12) defining a fluid flow path between fluid inlet (14) and fluid outlet (16), with the cross-sectional area of the fluid flow path expanding in the direction towards the fluid outlet (16).