Abstract
Exhaled nitric oxide (NO) is an important biomarker in asthma and other respiratory disorders. The optical performance of a NO/CO2 sensor employing integrated cavity output spectroscopy (ICOS) with a quantum cascade laser operating at 5.22 μm capable of real-time NO and CO2 measurements in a single breath cycle is reported. A NO noise-equivalent concentration of 0.4 ppb within a 1-sec integration time is achieved. The off-axis ICOS sensor performance is compared to a chemiluminescent NO analyzer and a nondispersive infrared (NDIR) CO2 absorption capnograph. Differences between the gas analyzers are assessed by the Bland-Altman method to estimate the expected variability between the gas sensors. The off-axis ICOS sensor measurements are in good agreement with the data acquired with the two commercial gas analyzers. This work demonstrates the performance characteristics and merits of mid-infrared spectroscopy for exhaled breath analysis.
Original language | English (US) |
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Article number | 034034 |
Journal | Journal of Biomedical Optics |
Volume | 12 |
Issue number | 3 |
DOIs | |
State | Published - May 2007 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Atomic and Molecular Physics, and Optics
- Biomedical Engineering
Keywords
- Breath analysis
- Carbon dioxide
- Chemiluminescence
- Integrated cavity output spectroscopy
- Nitric oxide
- Quantum cascade laser