Radially Constricted Tracheal Tube Sealing Cuff
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Solution Overview
Problem
High-volume/low-pressure tracheal tube cuffs are prone to forming open channels between the cuff and the trachea, leading to potential aspiration and increased risk of ventilator-associated pneumonia, while thin-walled cuffs are costly and limited in material choices due to tear-resistance and water permeability issues.
Innovation Solution
A sealing cuff with a radially constricted design, featuring a center portion with a larger radial extent than the proximal and distal portions, and an inflatable balloon with constraining elements to prevent expansion, reducing the risk of channel formation and allowing for thicker walls and a broader material selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If high-volume/low-pressure cuffs are used to reduce applied pressure and increase contact area, then the pressure on tracheal tissue is reduced, but open channels or grooves form at the interface leading to aspiration risk
Solution Approach 1:
The cuff design incorporates a radially constricted portion with different geometric properties (smaller radial extent) compared to the proximal and distal portions. This local geometric variation creates a specific contact pattern with the trachea that prevents channel formation while maintaining appropriate pressure distribution. The constricted portion acts as a barrier to liquid migration through the cuff-trachea interface.
Solution Approach 2:
The invention introduces a radial dimension variation by constricting the cuff in the radial direction at the constricted portion. This dimensional change (smaller radial extent at constricted portion compared to proximal and distal portions) creates a geometric feature that prevents the formation of open channels along the axial direction, thereby eliminating the aspiration pathway while maintaining the high-volume/low-pressure characteristic.
2Object-affected harmful factors
If thin-walled cuffs are used to reduce channel cross-sectional area and prevent aspiration, then liquid aspiration is prevented, but manufacturing cost increases and material choices are limited due to tear-resistance requirements
Solution Approach 1:
The cuff design incorporates a radially constricted portion with different geometric properties (smaller radial extent) compared to the proximal and distal portions. This local geometric variation creates a specific contact pattern with the trachea that prevents channel formation while maintaining appropriate pressure distribution. The constricted portion acts as a barrier to liquid migration through the cuff-trachea interface.
Solution Approach 2:
The invention introduces a radial dimension variation by constricting the cuff in the radial direction at the constricted portion. This dimensional change (smaller radial extent at constricted portion compared to proximal and distal portions) creates a geometric feature that prevents the formation of open channels along the axial direction, thereby eliminating the aspiration pathway while maintaining the high-volume/low-pressure characteristic.
3Strength
If polyurethane material is used for the cuff to provide tear-resistance, then the cuff is durable, but water permeability causes water accumulation within the cuffs over time
Solution Approach 1:
The invention specifies that the cuff may be made from silicone material instead of polyurethane. Silicone provides a different set of properties: it maintains adequate tear-resistance while being impermeable to water, thus preventing water accumulation. This material substitution resolves the contradiction between durability and water resistance.
Solution Approach 2:
The invention changes the material parameter from polyurethane to silicone, which fundamentally alters the permeability characteristic while maintaining mechanical strength. This parameter change (material selection) resolves the contradiction by finding a material that simultaneously provides tear-resistance and water impermeability.
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 cuff effectively prevents channel formation at the trachea interface, reducing the risk of aspiration and pneumonia, while being easier and less costly to manufacture with a wider range of material options.
Implementation Method 1
The sealing cuff comprises an expandable body that is configured to be expanded from a collapse state to an expanded state
Data Source
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AI summary
The invention relates to a sealing cuff (200) for a tracheal tube and a tracheal ventilation device. The sealing cuff comprises an expandable body (102) that is configured to be expanded from a collapsed state to an expanded state. The expandable body comprises an axial opening (104) that extends through the expandable body along an axial direction and is configured to receive a tracheal tube. The expandable body comprises a proximal portion (106), a center portion (108) and a distal portion (110) that are arranged along the axial direction and surround the axial opening. The proximal portion comprises a radially constricted portion (106B) adjacent to the center portion. A radial extent w2 of the radially constricted portion perpendicular to the axial direction is less than 75% of a radial extent w1 of the proximal portion and less than 75% of a radial extent w3 of the center portion in the expanded state. The distal portion comprises a radially constricted portion (110B) adjacent to the center portion. A radial extent w4 of the radially constricted portion perpendicular to the axial direction is less than 75% of a radial extent w5 of the distal portion and less than 75% of the radial extent w3 of the center portion in the expanded state.