Breath hydrogen (H2) and methane (CH4) monitoring play an important role in the diagnosis of gastrointestinal disorders, such as lactose intolerance and small intestinal bacterial overgrowth (SIBO). In this paper, the photoacoustic spectroscopy method is used for H2 gas and CH4 gas detection. We present a novel approach for H2 gas concentration measurement, which is the linear relationship between the resonant frequency of breath carbon dioxide (CO2) and the H2 concentration in a resonant photoacoustic cell. Experimental results show that the minimum detectable limits of H2, CH4, and CO2 are calculated to be 8.86, 0.56, and 145.14 ppm, respectively, which can meet the requirements of breath diagnosis.
Keywords: SIBO; exhaled breath; multigas detection; photoacoustic spectroscopy; resonant frequency tracking.