Variable Respiratory Restrictor Slider for Adjustable Inspiratory Resistance

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Solution Overview

Problem

Existing respiratory therapy devices for patients with mucus hyper-secretion and retention lack the ability to adjust inspiratory resistance, leading to either excessive or insufficient resistance for individual patients, which can hinder effective mucus clearance.

Innovation Solution

A variable restrictor is integrated into the inhalation path of the respiratory therapy assembly, allowing users to adjust the inhalation flow resistance using a slider, providing a customizable resistance that complements the existing expiratory oscillatory positive pressure therapy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed resistance is provided in existing respiratory therapy devices, then the device structure is simple, but the device cannot be adjusted to individual patient needs leading to either excessive or insufficient resistance

Engineering Contradiction:
Improveadjustability of inspiratory resistanceVSAvoidstructure of respiratory therapy device
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by introducing a movable slider that can be adjusted along a guide surface to vary the restriction aperture size. This transforms the fixed resistance structure into a dynamic, adjustable one, allowing the resistance to inhalation flow to be customized for individual patient needs while maintaining a relatively simple overall device structure.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If variable restrictor with slider is added to provide adjustable inspiratory resistance, then adaptability to individual patients is improved, but device complexity increases

Engineering Contradiction:
Improvecustomization of resistanceVSAvoidnumber of components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by separating the variable restrictor into distinct functional components: a housing, a slider, a guide surface, and aperture formations. This modular segmentation allows each component to perform its specific function independently, making the adjustable resistance mechanism easier to manufacture, assemble, and maintain while providing the needed customization capability.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If slider position is adjusted to vary restriction aperture, then inspiratory resistance can be customized, but ease of operation may be reduced

Engineering Contradiction:
Improvepersonalized resistance adjustmentVSAvoidadjustment mechanism operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies the self-service principle by enabling the patient to directly adjust the slider position themselves based on their own breathing needs. The straightforward slider-along-guide-surface mechanism allows users to independently customize their resistance without requiring complex controls or assistance, empowering them to self-regulate their therapy.

Inventive Principle:
Principle #25Self-service

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 solution enables personalized resistance adjustment, maximizing shear forces to effectively clear mucus from the lungs by allowing users to tailor inspiratory resistance according to their lung compliance and resistance, thereby enhancing mucus clearance.

Implementation Method 1

The aperture 113 supports an expiratory non-return valve 114, such as a flexible flap valve, which allows air to flow from the restrictor R into the therapy device 20 but prevents any substantial flow in the opposite direction

Methodology Applied
Scientific EffectOne-way valve mechanism: Valve

Implementation Method 2

This aperture 115 is covered by an inspiratory non-return valve 116, such as a flexible flap valve, that allows air to be drawn through the aperture into the mouthpiece 110 but substantially prevents air flow in the opposite direction

Methodology Applied
Scientific EffectOne-way valve mechanism: Valve

Implementation Method 3

The restrictor R also includes a slider 117 in the form of a generally rectangular plate extending laterally of the housing 100 through a slot 118 in its left-hand end so that the left-hand end 119 of the slider projects from the housing and its right-hand end 120 extends within the housing across the bore of the inspiratory aperture 115

Methodology Applied
Scientific EffectFlow restriction through movable obstruction: Drag

Implementation Method 4

The air flow tube 6 has an outlet opening 10 with a non-linear profile that is opened and closed by a conical valve element 11 mounted on a rocker arm 12 pivoted midway along its length about a transverse axis

Methodology Applied
Scientific EffectMechanical oscillation: Harmonic Oscillator

Implementation Method 5

The far end of the rocker arm 12 carries an iron pin 13 that interacts with the magnetic field produced by a permanent magnet (not visible) mounted on an adjustable support frame 14

Methodology Applied
Scientific EffectMagnetic interaction: Magnetic Field

Data Source

PatentEP3169412B1Respiratory therapy assemblies
Publication Date: 2019.04.24 ICU MEDICAL INTERNATIONAL LTD
  • EP3169412B1 patent drawingFigure 1
  • EP3169412B1 patent drawingFigure 2
  • EP3169412B1 patent drawingFigure 3~4

AI summary

An expiratory respiratory therapy assembly includes a therapy device (20) that provides an oscillating resistance to expiratory flow. A variable restrictor R is connected to the breathing inlet (7) of the therapy device. The restrictor R includes a manually-displaceable slider (117) that is movable to cover varying proportions of an inspiratory aperture (115) in the restrictor so as to provide a variable resistance to inspiratory flow.