Volatile anesthetic gas concentration sensing using flow sensor fusion for use in Austere settings

Area of Science:

• Anesthesiology
• Biomedical Engineering
• Sensor Technology

Background:

• Volatile anesthetic monitoring is crucial for patient safety.
• Conventional methods like infrared spectroscopy can be expensive and complex.
• Flow sensors' sensitivity to anesthetics presents an opportunity for alternative monitoring.

Purpose of the Study:

• To assess the feasibility of using fused flow sensor data for monitoring volatile anesthetic concentrations.
• To explore a low-cost, low-maintenance alternative to existing anesthetic gas monitoring technologies.

Main Methods:

• Eight different flow sensors were tested with isoflurane, sevoflurane, and desflurane at various concentrations.
• Sensor pairs were analyzed using leave-one-out cross-validation.
• Bland-Altman analysis evaluated the performance of sensor pairs.

Main Results:

• Several flow sensor pairs demonstrated limits of agreement comparable to commercial infrared spectrometers.
• Ultrasonic and orifice-plate flowmeters formed the most viable sensor combinations for all tested anesthetic gases.
• Flow sensor fusion is a feasible method for measuring anesthetic gas concentrations.

Conclusions:

• Flow sensor fusion presents a viable, cost-effective, and low-maintenance alternative to infrared spectroscopy for monitoring volatile anesthetic gases.
• Further research is needed to validate performance in clinical settings beyond steady-state conditions in 100% oxygen.