Performance of an exhaled nitric oxide and carbon dioxide sensor using quantum cascade laser-based integrated cavity output spectroscopy

J Biomed Opt. 2007 May-Jun;12(3):034034. doi: 10.1117/1.2747608.

Abstract

Exhaled nitric oxide (NO) is an important biomarker in asthma and other respiratory disorders. The optical performance of a NOCO(2) sensor employing integrated cavity output spectroscopy (ICOS) with a quantum cascade laser operating at 5.22 microm capable of real-time NO and CO(2) 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) CO(2) 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.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Breath Tests / instrumentation*
  • Breath Tests / methods
  • Carbon Dioxide / analysis*
  • Equipment Design
  • Equipment Failure Analysis
  • Female
  • Humans
  • Lasers*
  • Male
  • Middle Aged
  • Nitric Oxide / analysis*
  • Pulmonary Disease, Chronic Obstructive / diagnosis*
  • Pulmonary Disease, Chronic Obstructive / metabolism*
  • Pulmonary Gas Exchange
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spectrum Analysis / instrumentation*
  • Spectrum Analysis / methods
  • Systems Integration

Substances

  • Carbon Dioxide
  • Nitric Oxide