Photoacoustic Spectroscopy-Based Breath Analysis for SIBO

Ppb-Level Ammonia Sensor for Exhaled Breath Diagnosis Based on UV-DOAS Combined with Spectral Reconstruction Fitting Neural Network

“…However, it is challenging to avoid the interference caused by other components in EB and to further improve the measurement accuracy in the exhaled breath environment because the components of EB are complex and the concentration of breath NH 3 reaches the ppb level. Photoacoustic spectroscopy is a technique that utilizes a combination of optical absorption effects and acoustic signals to detect gas components at very low concentrations. − Quartz tuning fork laser spectroscopy uses the high-frequency stability of a quartz tuning fork as a frequency reference to measure the concentration of gases by means of an FM laser and optical absorption effects. , As for both techniques, however, there is still a long way to go before interference caused by gases in EB and environmental factors in practical applications can be eliminated. Sensors based on FTIR can achieve high-precision detection of NH 3 with absorption characteristics in the range 700–1300 cm –1 .…”