Colorimetric Sensor Calibration via Humidification and Reference Gas

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Chemical based colorimetric techniques for measuring carbon dioxide concentrations in breath face challenges such as slow response times, batch-to-batch variations, sensitivity to environmental factors, and calibration complexities, making them less reliable for real-time monitoring, especially outside clinical settings.

Innovation Solution

A method and system for calibrating chemical colorimetric indicators using a combination of humidification and exposure to gases with known CO2 concentrations, allowing for quick and accurate characterization and calibration, enabling reliable quantitative CO2 measurements in a user-friendly and cost-effective manner.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If chemical colorimetric indicators are used for CO2 measurement, then cost is reduced and simplicity is achieved, but response time is slow and accuracy is compromised

Engineering Contradiction:
ImprovecostVSAvoidresponse time
Core Design Contradiction:
Ease of manufactureVSSpeed

Solution Approach 1:

The patent modifies the chemical indicator formulation by changing parameters such as indicator concentration, carrier gas composition, and chamber geometry to optimize the balance between response time and cost-effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically adjusts measurement parameters including flow rate, indicator exposure time, and signal processing thresholds to adapt to different breathing patterns and CO2 concentrations in real-time

Inventive Principle:
Principle #15Dynamics

2Device complexity

If chemical colorimetric indicators are used, then device complexity is reduced, but measurement precision and reliability are insufficient for real-time monitoring

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms where the system continuously monitors indicator response, compares it against reference values, and automatically adjusts measurement parameters or triggers recalibration to maintain precision without increasing device complexity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces complex mechanical calibration mechanisms with electronic signal processing and algorithmic corrections that achieve precise measurements through software rather than hardware complexity

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

3Productivity

If colorimetric indicators are manufactured with standard protocols, then manufacturing efficiency is maintained, but batch-to-batch variations and sensitivity to environmental factors occur

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidreliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary characterization and calibration of colorimetric indicators during manufacturing, establishing baseline performance parameters and compensation factors that ensure consistent reliability across batches without reducing manufacturing efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically compensates for environmental variations by adjusting measurement parameters based on recorded temperature, humidity, and pressure conditions, maintaining reliability across different environmental conditions

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If calibration is performed manually after removal from packaging, then user flexibility is improved, but calibration complexity and potential for error increase

Engineering Contradiction:
Improveuser flexibilityVSAvoidcalibration complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements self-service calibration where the system automatically performs calibration procedures using built-in reference gases and algorithms, eliminating manual intervention while maintaining user flexibility through automated guided calibration workflows

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system introduces intermediary calibration reference gases and standardized protocols that mediate between the user and the complex calibration process, simplifying the procedure while maintaining calibration accuracy through standardized intermediate steps

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method improves the reliability, accuracy, and ease of use of chemical colorimetric indicators by enabling rapid calibration, reducing batch-to-batch variations, and enhancing responsiveness to CO2 concentrations, making them suitable for non-clinical applications like breathing therapy.

Implementation Method 1

chemical based colorimetric techniques for measuring carbon dioxide concentrations in breath

Methodology Applied
Scientific EffectColorimetric detection: Photochromism

Implementation Method 2

humidifying a chemical colorimetric indicator

Methodology Applied
Scientific EffectHumidification: Evaporation

Data Source

PatentEP3304494B1Devices and methods for calibrating a colorimetric sensor
Publication Date: 2020.06.17 PALO ALTO HEALTH SCI
  • EP3304494B1 patent drawingFigure 1
  • EP3304494B1 patent drawingFigure 2
  • EP3304494B1 patent drawingFigure 3A

AI summary

Quantitative colorimetric carbon dioxide measurement and measurement systems and methods are disclosed. The methods can include methods for calibrating a chemical colorimetric indicator used in the quantitative colorimetric carbon dioxide measurement system. Apparatuses are disclosed including a cartridge comprising a chemical colorimetric indicator that is configured to removably engage with a quantitative colorimetric measurement system. Cartridges containing a sealed container comprising a reference gas with a known concentration of carbon dioxide are also disclosed. Systems and methods for humidifying the chemical colorimetric indicator are also provided. Methods for using the systems are also disclosed including providing a breathing therapy to a patient or user.