Method for precise comparison of isotopic CO2 content in breath samples based on laser spectral analysis

Method of precise isotopic contents comparison in breath samples based on use of laser spectral analysis is proposed. It permits precise analysis of relative 13CO2 / 12CO2 concentration changes in exhaled air caused by isotopic breath tests. By computer modeling of an algorithm of spectral data processing, a noise effect on the result of the analysis is investigated, and the best spectral regions are determined. Several approaches to eliminate interferences of different origin are proposed.