Develop a Diode Laser Spectroscopy System for Continuous Monitoring of Certain Gases in the Expire Air and Blood with a High Degree of Accuracy.

Development of a monitor prototype to accurately measure medical gases such as O2 and CO2 content in the expired air is the objective of this program. By using the frequency modulation spectroscopy technique, we have fabricated a diode laser based sensor prototype for measuring O2 content in different concentration gas mixtures and the expired air. The prototype provides the good detection accuracy and signal-to-noise ratio. For an application purpose of breath-by-breath oxygen content monitoring, the death volume of the gas cell in the current sensor is still big and the related sample replacement time is still relatively long. The single board lock-in amplifier has to be improved. Further modifications on the lock-in amplifier and the gas cell are underway.
Original contains color plates: All DTIC/NTIS reproductions will be in black and white.