人体呼吸CO₂浓度监测模型及其实验验证

Aiming at the monitoring of the concentration of human respiratory CO₂, this paper reasonably simplifies the human respiratory process from the perspective of physics. Based on the gas exchange in the lungs during respiratory process and the relationship between the lung gas volume and concentration, the human lung respiratory model was established. For End-Tidal Carbon Dioxide (ETCO₂) monitoring, the difference between the sensor measurement and the actual situation in the lung was analyzed, and the CO₂ sensor model was established. By building a mainstream non-dispersive infrared (NDIR) respiratory CO₂ concentration monitoring system for confirmatory experiments, the system uses infrared LEDs and PbSe infrared detectors. The error between the actual measurement result of ETCO₂ concentration and the theoretical model is less than 0.3%, and the feature matching degree is high, which verifies the applicability of the model. It can monitor the CO₂ concentration of human breathing, and can reflect the capnography of the subject in real time.