Monitoring of rapid blood pH variations by CO detection in breath with tunable diode laser

Detection of endogenous carbon monoxide content in breath with tunable diode lasers (TDL) was proposed for noninvasive monitoring of rapid blood pH variation. Applied approach is based on high sensitivity of the haemoglobin and myoglobin affinity for CO to blood pH value and an ability to detect rapidly small variations of CO content in expired air. Breath CO absorption in 4.7 micrometers spectral region was carefully measured using PbSSe tunable diode laser that can provide 1 ppb CO concentration sensitivity and 10 s time constant. Applied TDL gas analyzer was used to monitor expired air of studied persons in physiological tests including hyperventilation and physical load. Simultaneous blood tests were conducted to demonstrate correlation between blood and breath chemical parameters.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.