Capnograph adopts side stream method to measure the end-tidal carbon dioxide, airway respiration rate and other parameters. It can detect pulmonary ventilation function and reflect the circulation and pulmonary blood flow as well as indirectly reflect the alveolar ventilation standard. Meanwhile, it can also detect the blood oxygen saturation and pulse. The Capnograph is applicable for use in pre-hospital emergency transfer, emergency, ICU, operating room, neonatology, respiratory department and other occasions. The application population is adult, pediatric and neonate patients.