Pulsating Tracheal Tube Cuff Design for Reduced Trauma

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Solution Overview

Problem

Existing tracheal tubes with pressure-controlled sealing cuffs continue to cause traumatic pressure damage to the trachea and pose a high risk of infection due to secretion accumulation and aspiration, despite previous design improvements.

Innovation Solution

A tracheal tube design where the ventilation cannula opens into the breathing tube away from the sealing cuff, with a larger jacket sealing surface and a suction device arranged orally, allowing the sealing cuff to pulsate with the ventilation rhythm, enabling partial collapse during expiration and facilitating oral exhalation, which reduces trauma and infection risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sealing cuff is inflated to ensure a continuous seal between the breathing tube and the trachea, then the seal against aspiration is improved, but the traumatic pressure on the trachea increases

Engineering Contradiction:
Improveseal against aspirationVSAvoidtraumatic pressure on trachea
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The sealing cuff is designed to inflate and deflate periodically in synchronization with the ventilator's respiratory cycles. During inspiration, the cuff inflates to provide a seal; during expiration, it deflates to reduce pressure on the trachea. This periodic action maintains the seal against aspiration while eliminating continuous traumatic pressure.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The sealing cuff transitions from a static continuous seal to a dynamic pulsating seal that adapts to the respiratory cycle. The cuff's volume and pressure change dynamically between inspiration and expiration, allowing it to provide sealing function when needed while reducing pressure during other phases.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the sealing cuff is inflated to prevent backflow of respiratory gas orally, then the seal is improved, but the risk of secretion accumulation and aspiration increases

Engineering Contradiction:
Improveprevent backflow of respiratory gasVSAvoidsecretion accumulation and aspiration risk
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The sealing cuff inflates during inspiration to prevent backflow of respiratory gas, then deflates during expiration to allow secretion drainage. This periodic inflation-deflation cycle maintains the seal against gas backflow while creating periods when secretions can drain orally, reducing accumulation and aspiration risk.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system maintains continuous sealing action during the inspiratory phase when it is most needed to prevent gas backflow, while allowing the deflatory phase to continuously drain secretions. The useful sealing action is maintained without interruption to the respiratory cycle, while secretion drainage occurs during the natural expiratory phase.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of manufacture

If the ventilation cannula opens into the sealing cuff, then the cuff can be inflated with respiratory gas, but the pressure control and trauma reduction are compromised

Engineering Contradiction:
Improvecuff inflation with respiratory gasVSAvoidpressure control and trauma
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The ventilation cannula is extracted from the sealing cuff and repositioned to open directly into the breathing tube away from the cuff. This separation allows the cuff to be inflated with a controlled portion of respiratory gas while the main ventilation flow remains independent, enabling better pressure control and reduced trauma.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The gas flow path is segmented into two separate channels: one for cuff inflation (through the ventilation cannula) and one for main ventilation (through the breathing tube). This segmentation allows independent control of cuff pressure and ventilation flow, improving both pressure control and trauma reduction.

Inventive Principle:
Principle #1Segmentation

4Reliability

If the jacket sealing surface is made larger than the pulmonary annular end face, then the seal against the trachea wall is improved, but the complexity of the sealing mechanism increases

Engineering Contradiction:
Improveseal against trachea wallVSAvoidsealing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing cuff is designed with a spherical or oval geometry where the jacket sealing surface area is naturally larger than the pulmonary annular end face. This curved geometry provides a larger contact area for sealing against the trachea wall while maintaining a simple, elegant structure without complex mechanisms.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 pulsating sealing cuff reduces traumatic pressure on the trachea, minimizes the risk of aspiration, and allows for easier secretion transport and voice production during expiration, enhancing patient comfort and reducing the need for frequent bronchial toilet procedures.

Implementation Method 1

the sealing cuff is arranged around the ventilation hose on the part that can be inserted into the trachea... the sealing cuff to pulsate with the ventilation rhythm, enabling partial collapse during expiration

Methodology Applied
Scientific EffectPressure-controlled ventilation: Pressure Gradient

Implementation Method 2

at least one Ventilation cannula, which opens into the sealing sleeve... the ventilation cannula opens into the breathing tube away from the sealing cuff

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Implementation Method 3

the sealing cuff is not inserted into the trachea in the inflated state, but only filled with air as soon as the breathing tube is in its intended position... the sealing cuff to pulsate with the ventilation rhythm

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2179761B1Tracheal tube
Publication Date: 2011.12.14 WILLY RUSCH GMBH
  • EP2179761B1 patent drawingFigure 1
  • EP2179761B1 patent drawingFigure 2~3
  • EP2179761B1 patent drawingFigure 4~5

AI summary

The tube has a breathing tube (2) partially insertable into trachea, and a sealing sleeve (4) arranged at a part insertable into trachea (3) around the breathing tube. An aeration cannula (8) opens into the sleeve, and an end (10) of the cannula averting the sleeve opens into the breathing tube. A casing sealing surface (5) of the sleeve is greater than an annular front surface (6) of the sleeve, and a suction cannula (12) is arranged upstream of the sleeve. An inner wall of the sleeve completely lies at the breathing tube.