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24 April 1996 Potential for a silicon probe in a Raman spectroscopic general-anesthetic sensor
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Currently there is no direct method for measuring anesthetic levels in blood or tissue. Efforts are underway to develop a Raman spectroscopy-based sensor for general anesthetics using a polymeric probe. Signal enhancement, needed because of the inherently weak Raman signal, can be obtained by absorption of anesthetics into and recirculation of photons within the probe. Commercially available photopolymerizable silicones might have potential in the development of such probes since they are conducive to ring formation. Before attempting this, however, it is necessary to understand how the interfering silicone peaks will affect the signal-to-noise ratio of the anesthetic peaks and, ultimately, the sensor's detection limit. To this end, studies were performed on liquid anesthetics in silicon oil. The anesthetic C-H stretch peaks near 3000 cm-1 were obscured by those of the silicone. However, detection limits of 1.2, 1.5, and 1.2 MAC were observed for halothane, isoflurane, and enflurane, respectively, by monitoring a lower wavenumber region (900 - 1300 cm-1). In addition, 0 - 5 MAC mixtures of anesthetics were studied. PLS predictive models generated from MSC- corrected validation spectra predicted anesthetic levels relatively well for these mixtures (R2 equals 0.969, 0.984, and 0.979 for halothane, isoflurane, and enflurane, respectively); differences of 1 MAC were discernable.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Julie R. Parnell and Paul Yager "Potential for a silicon probe in a Raman spectroscopic general-anesthetic sensor", Proc. SPIE 2676, Biomedical Sensing, Imaging, and Tracking Technologies I, (24 April 1996);

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