A SIGNAL ENHANCED PORTABLE RAMAN PROBE FOR ANESTHETIC GAS MONITORING

• Main Authors: S. Schlüter, S. Asbach, N. Popovska-Leipertz, T. Seeger, A. Leipertz
• Format: Article
• Language: English
• Published: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) 2015-03-01
• Series: Naučno-tehničeskij Vestnik Informacionnyh Tehnologij, Mehaniki i Optiki
• Subjects: Raman scattering; multi species gas sensor; low pressure; anesthesia monitor; multipass cavity; short sampling time; simultaneous online concentration information; Raman scattering; multi species gas sensor; low pressure; anesthesia monitor; multipass cavity; short sampling time; simultaneous online concentration information
• Online Access: http://ntv.ifmo.ru/file/article/12845.pdf

The spontaneous Raman scattering technique is an excellent tool for a quantitative analysis of multi-species gas mixtures. It is a noninvasive optical method for species identification and gas phase concentration measurement of all Raman active molecules, since the intensity of the species specific Raman signal is linearly dependent on the concentration. Applying a continuous wave (CW) laser it typically takes a few seconds to capture a gas phase Raman spectrum at room temperature. Nevertheless in contrast to these advantages the weak Raman signal intensity is a major drawback. Thus, it is still challenging to detect gas phase Raman spectra in alow-pressure regime with a temporal resolution of only a few 100 ms. In this work a fully functional gas phase Raman system for measurements in the low-pressure regime (p ≥ 980 hPa (absolute)) is presented. It overcomes the drawback of a weak Raman signal by using a multipass cavity. A description of the sensor setup and of the multipass arrangement will be presented. Moreover the complete functionality of the sensor system will be demonstrated by measurements at an anesthesia simulator under clinical relevant conditions and in comparison to a conventional gas monitor.