Raman spectroscopy of airway gases

摘要

Method and apparatus for determining the composition and concentration of gases present in a patient's airway by measurement of the spectrum of Raman scattered light from these gases. The efficiency is improved by collecting Raman scattered light generated outside the collection region. The gases present are assumed to be drawn from a predetermined set of gases with known Raman scattering spectra, and the concentrations are determined by solution of a matrix equation Ac=b, where the c vector components are the unknown concentrations and the b vector components are determined from measurements of the Raman scattering intensifies in a plurality of wavelength or wavenumber intervals. The linear system of equations represented by the matrix equation may be overdetermined and may require solution by non-conventional methods, such as singular value decomposition.