Inspiratory CO2 Blending Control for Stable PaCO2 Delivery

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Solution Overview

Problem

Traditional methods for delivering CO2 to maintain target PaCO2 levels in respiratory gases are unreliable, as they fail to accurately control CO2 concentrations at the physiological site of action, leading to uncertainties in measuring vascular reactivity and other physiological responses.

Innovation Solution

A method and system that continuously maintain a target CO2 concentration in the inspiratory gas stream by calculating and controlling incremental volumes of CO2-containing gas (Gn) to be delivered in tandem with a second gas (G0), ensuring accurate cumulative CO2 levels in the respiratory gas (GR) through a respiratory gas delivery system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If CO2 is infused into a mask to change PaCO2, then exhaled PCO2 changes, but the actual PaCO2 at the physiological site of action is not reliably changed

Engineering Contradiction:
Improvemeasurement of PaCO2VSAvoidreliability of PaCO2 control
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system continuously monitors actual CO2 delivery and compares it to the target CO2 concentration, then adjusts the CO2 addition rate in real-time to maintain accurate PaCO2 levels. This closed-loop feedback control ensures reliable PaCO2 control despite variations in patient breathing patterns

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces traditional mechanical mask infusion methods with an electronic control system that uses sensors, processors, and electronic valves to precisely regulate CO2 delivery. This substitution of mechanical systems with electronic control enables accurate measurement and reliable maintenance of target CO2 concentrations

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If traditional CO2 delivery methods are used, then the system is simple to operate, but the CO2 concentration control is inaccurate

Engineering Contradiction:
ImproveCO2 concentration control precisionVSAvoidgas delivery system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The gas delivery system is divided into separate functional modules: a CO2 delivery module, an inspiratory gas module, sensors for monitoring volumes and concentrations, and a control module. This segmentation allows each component to be optimized for its specific function while maintaining overall system precision

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate computational steps where the processor calculates incremental CO2 volumes based on target concentrations and actual delivery measurements. This intermediary computational layer translates simple operational inputs into precise CO2 concentration control

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If CO2 is delivered without continuous monitoring, then the device complexity is reduced, but the reliability of maintaining target CO2 levels deteriorates

Engineering Contradiction:
Improvereliability of target CO2 maintenanceVSAvoidmonitoring and control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system incorporates continuous monitoring of cumulative CO2 volumes delivered and inspiratory gas volumes, with this data fed back to the control module to adjust CO2 delivery in real-time. This feedback mechanism ensures reliable maintenance of target CO2 levels throughout the breathing cycle

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system automatically monitors and adjusts CO2 delivery without requiring manual intervention. The control module self-regulates the CO2 addition rate based on real-time measurements, making the system self-correcting and reliable

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2696927B1Gas delivery apparatus
Publication Date: 2021.11.10 THORNHILL SCI INC
  • EP2696927B1 patent drawingFigure 1a
  • EP2696927B1 patent drawingFigure 1b
  • EP2696927B1 patent drawingFigure 1c

AI summary

An apparatus, method and system for delivering C02 into an inspiratory gas stream to formulate a blended respiratory gas in a manner that continuously maintains a target C02 concentration in a volume of the inspired respiratory gas, for example, over the course of a breath or a volumetrically definable part thereof or a series of partial or full breaths.