Düsseldorf 2007 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 32: Poster Laser in Medizin und Umwelttechnik

Q 32.1: Poster

Dienstag, 20. März 2007, 16:30–18:30, Poster C

Laser Spectroscopic Online Monitoring of Ethane Traces in Exhaled Breath — •Sven Thelen, Manfred Tamminga, Peter Hering, and Manfred Mürtz — Institut für Lasermedizin, Universitätsstr. 1, 40225 Düsseldorf, www.ilm.uni-duesseldorf.de

The quantitative and time resolved analysis of trace gases contained in human breath is of considerable interest for medical diagnostics. An important example is ethane, a bio-marker for the free radical induced lipid peroxidation in the human body. This chemical process is related to diseases like Alzheimer’s and artherosclerosis, therefore a rapid and non-invasive detection of ethane is very desirable.
Our detection method is based on Cavity Leak-Out Spectroscopy (CALOS), a highly sensitive and specific variant of laser absorption spectroscopy well suited for time resolved breath measurements. As laser source we have implemented a Difference Frequency Generation (DFG) system (Δν = 3.30-3.67 µm, P = 280 µW).
We currently achieve an ethane detection limit of 400 ppt or 0.4 nl/l and a time resolution of better than 1 s [1]. We present the latest results of time-resolved online measurements of single breath exhalations of ethane.

[1] D. Halmer et al., Appl. Phys. B 85, 437 (2006).