Branching Unit Minimizing Dead Volume for Respiratory Gas Delivery
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Solution Overview
Problem
Conventional breathing gas delivery systems have high mechanical dead volume, which interferes with gas exchange in the lungs, especially in smaller patients, leading to rebreathing of used gas and inadequate ventilation, and existing gas analyzing techniques are inadequate for high respiration rates and small tidal volumes.
Innovation Solution
A branching unit with a reduced dead volume of less than 1 ml for the respiratory gas delivery system, combined with a compact airway adapter and gas analyzer, designed to minimize mechanical dead volume and facilitate accurate gas component measurement, particularly suitable for neonates and pediatric patients with high respiration rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional breathing circuit with Y-piece and airway adapter is used, then gas analysis can be performed, but the mechanical dead volume is large causing rebreathing of used gas
Solution Approach 1:
The airway adapter is integrated directly into the branching unit to form a unified structure, eliminating separate connection components and minimizing the overall mechanical dead volume while maintaining gas analysis functionality
Solution Approach 2:
The design extracts and eliminates unnecessary intermediate components and connection spaces between the airway adapter and branching unit, removing sources of dead volume that cause gas rebreathing
2Reliability
If the dead volume is reduced to less than 1 ml, then gas exchange is improved, but the device complexity increases
Solution Approach 1:
The airway adapter and branching unit are merged into a single integrated component, reducing dead volume through eliminated interfaces while the multi-limb branching structure provides the necessary functional complexity for gas distribution
Solution Approach 2:
The branching unit employs different limb configurations with specific local characteristics (inspiratory limb, expiratory limb, common limb) to optimize gas flow paths locally while maintaining overall compactness
3Volume of stationary object
If a compact airway adapter is used, then dead volume is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The airway adapter is integrated as part of the branching unit structure, allowing the compact design to be manufactured as a single piece or pre-assembled unit, thereby reducing the cumulative tolerance stack-up that would occur with multiple separate components
Data Source
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AI summary
A branching unit for delivering a respiratory gas of a subject is disclosed herein. The branching unit includes a first limb (123) for delivering an expiratory gas during an expiratory phase and a second limb (122) for delivering an inspiratory gas during an inspiratory phase. The branching unit also includes a third limb (121) for delivering both the expiratory gas and the inspiratory gas and a common branching point (126) for the first limb, the second limb and the third limb. The first limb, the second limb and the third limb include a volume for the respiratory gas and which volume includes both an active volume with the gas exchanging between the inspiratory phase and the expiratory phase and a dead volume for the respiratory gas with insufficient gas exchange from the inspiratory phase to the expiratory phase and the dead volume being less than 1 ml.