Development of a CO₂ Sensor for Extracorporeal Life Support Applications

Area of Science:

• Medical instrumentation
• Optical sensing technologies
• Respiratory monitoring

Background:

• Noninvasive carbon dioxide (CO2) monitoring is crucial in critical care, anesthesia, and extracorporeal life support (ECL S).
• Measuring CO2 in membrane oxygenator exhaust gas aids in evaluating treatment efficacy and device performance during ECCO2R, ECMO, and CPB.
• Existing methods may face challenges with accuracy and environmental factors like water vapor condensation.

Purpose of the Study:

• To develop and validate a novel optical sensor for precise CO2 concentration measurement in oxygenator exhaust gas.
• To integrate gas flow measurement and CO2 removal rate estimation capabilities into the sensor.
• To address and mitigate the impact of temperature and water vapor on sensor performance.

Main Methods:

• Development of a specialized optical sensor with an integrated heating module to prevent condensation.
• Characterization of sensor performance, including temperature effects on optical elements and a method for signal correction.
• Comparative analysis of the developed sensor against a standard clinical reference device in laboratory and in vivo settings.

Main Results:

• The new optical sensor accurately measures CO2 concentration in oxygenator exhaust gas.
• The sensor successfully measures gas flow and estimates the CO2 removal rate.
• Performance validation confirmed accuracy meeting ISO standards, demonstrating suitability for clinical use.
• A method to compensate for temperature-dependent signal variations was successfully implemented.

Conclusions:

• The developed optical sensor offers a reliable and accurate solution for monitoring CO2 in medical applications, particularly in extracorporeal life support.
• The integrated functionalities enhance its utility for assessing treatment progress and device performance.
• The sensor's accuracy and robustness make it suitable for routine clinical application, adhering to established standards.