Development of breath sampling system for detection of exhaled nitric oxide by Faraday modulation spectroscopy
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Technological developments over the years have resulted in many different techniques for detection of nitric oxide (NO) in both the atmosphere and from biological sources. One such technique is Faraday Modulation Spectroscopy (FAMOS), which is a laser-based spectroscopic technique for detection of paramagnetic molecules in gas phase. The technique uses a modulated magnetic field that introduce rotation of the polarization plane of linearly polarized laser light, which can be related to the concentration of the molecules. This enables sensitive and selective detection of paramagnetic gaseous compounds and the technique is thus well suited for detection of NO for biomedical applications in low concentrations which is essential for breath analysis.
In this thesis, a system for breath analysis is developed and coupled to a Faraday modulation spectrometer for sensitive detection of NO at 5.33 μm based on a room temperature continuous wave distributed feedback (DFB) QCL. It also provides a theoretical model of FAMOS utilizing the most sensitive Q3/2 (3/2 ) transition in NO. The results from this study indicate that the mid-infrared FAMOS system, which was built around a continuous wave (cw) quantum cascade laser (QCL) emitting light with an output power of approximately 70 mW, is fully capable of detection of ppb levels of NO in exhaled human breath.
Place, publisher, year, edition, pages
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:umu:diva-117140OAI: oai:DiVA.org:umu-117140DiVA: diva2:905517
Subject / course
Fysik D - examensarbete