Breath Analysis Using Laser Spectroscopy Techniques: Development And Future

As a promising new field of medicine and a new development direction of medical instrumentation, breath analysis offers noninvasive and real-time disease diagnostics and metabolic status monitoring potentially. Numerous breath biomarkers are detected and quantified so far by the utilization of gas chromatography-mass spectrum(GC-MS) technique. Recent advances in laser spectroscopic techniques and laser sources accelerate the development of breath analysis. Compared with the MS-based techniques, laser spectroscopic techniques have not only the high-sensitivity and high-selectivity, but also the advantageous features of real-time response, low instrument cost and point-of-care testing (POCT). In the approximately 35 established breath biomarkers, serious species in human breath are analyzed by laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS), cavity ringdown spectroscopy (CRDS), and photoacoustic spectroscopy (PAS). The spectral fingerprints of the measured biomarkers are spanned from the ultra violet to the mid-infrared spectral regions.