Minimally invasive image-based determination of the concentration of carbon dioxide (CO2) in exhaled breath

摘要

A system and method for image-based determination of the concentration of carbon dioxide (CO2) in exhaled breath is disclosed. In one embodiment, an image of the exhaled airflow of an individual of interest is received. The image is captured by means of a medium wavelength infrared camera system having an optical filter tuned to the CO2 infrared absorption band. The image is preprocessed to isolate a region of pixels containing the exhaled airflow, and intensity values of pixels in the identified region are normalized to a value of known radiation density, for example the nose or face of the individual. The image is analyzed to determine the CO2 concentration levels of the exhaled airflow using a calibration curve that relates pixel intensity to CO2 concentrations. The calibration curve is derived using a physics-based parametric model. The CO2 concentration levels are determined and transmitted to a computer workstation. Various embodiments are disclosed.