Real time detection of exhaled human breath using quantum cascade laser based sensor technology

Frank K. Tittel, Rafał Lewicki, Lei Dong, Kun Liu, Terence H. Risby, Steven Solga, Tim Schwartz

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Scopus citations


The development and performance of a cw, TE-cooled DFB quantum cascade laser based sensor for quantitative measurements of ammonia (NH 3) and nitric oxide (NO) concentrations present in exhaled breath will be reported. Human breath contains ∼ 500 different chemical species, usually at ultra low concentration levels, which can serve as biomarkers for the identification and monitoring of human diseases or wellness states. By monitoring NH 3 concentration levels in exhaled breath a fast, non-invasive diagnostic method for treatment of patients with liver and kidney disorders, is feasible. The NH 3 concentration measurements were performed with a 2f wavelength modulation quartz enhanced photoacoustic spectroscopy (QEPAS) technique, which is suitable for real time breath measurements, due to the fast gas exchange inside a compact QEPAS gas cell. A Hamamatsu air-cooled high heat load (HHL) packaged CW DFB-QCL is operated at 17.5°C, targeting the optimum interference free NH 3 absorption line at 967.35 cm -1 (λ∼10.34 μm), with ∼ 20 mW of optical power. The sensor architecture includes a reference cell, filled with a 2000 ppmv NH 3 :N 2 mixture at 130 Torr, which is used for absorption line-locking. A minimum detection limit (1σ) for the line locked NH 3 sensor is ∼ 6 ppbv (with a 1σ; 1 sec time resolution of the control electronics). This NH 3 sensor was installed in late 2010 and is being clinically tested at St. Luke's Hospital in Bethlehem, PA.

Original languageEnglish (US)
Title of host publicationPhotons Plus Ultrasound
Subtitle of host publicationImaging and Sensing 2012
StatePublished - Apr 9 2012
EventPhotons Plus Ultrasound: Imaging and Sensing 2012 - San Francisco, CA, United States
Duration: Jan 22 2012Jan 24 2012

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherPhotons Plus Ultrasound: Imaging and Sensing 2012
Country/TerritoryUnited States
CitySan Francisco, CA


  • Ammonia
  • Exhaled breath analysis
  • Nitric oxide
  • Quantum cascade lasers
  • Quartz enhanced photoacoustic spectroscopy
  • Trace gas detection

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Real time detection of exhaled human breath using quantum cascade laser based sensor technology'. Together they form a unique fingerprint.

Cite this