Luminescence lifetime-based carbon dioxide optical sensor for clinical applications

Area of Science:

• Biomedical Engineering
• Chemical Sensors
• Optical Sensing Technologies

Background:

• Accurate monitoring of partial pressure of carbon dioxide (pCO2) is crucial for critically ill patients.
• Existing pCO2 monitoring methods may have limitations in certain clinical settings.

Purpose of the Study:

• To develop and characterize novel optical planar and capillary-based carbon dioxide sensors.
• To enable real-time pCO2 monitoring in adipose tissue for critically ill patients.

Main Methods:

• Utilized phase fluorometry with a dual luminophore referencing scheme (DLR).
• Incorporated luminophores (HPTS and Ru(dpp)3(2+)) and a phase transfer agent (TOA-OH) into polymer matrices (silicone, Eudragit/PEG).
• Characterized sensor sensitivity, stability, and performance in aqueous solutions.

Main Results:

• Optimized sensor matrices (silicone and Eudragit/PEG) demonstrated significant phase shifts (up to 13° and 15°).
• Sensors achieved a pCO2 measurement range of 0-150 mmHg with 0.5 mmHg resolution.
• Accuracy was within +/-1 mmHg absolute or <7% of the read-out value.

Conclusions:

• Developed robust optical CO2 sensors suitable for pCO2 monitoring.
• The DLR-based phase fluorometry approach offers a promising method for clinical pCO2 sensing.
• Further validation in adipose tissue is required for clinical application.