Capnograph adopts mainstream 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 condition, as well as indirectly reflect the alveolar ventilation, which is applicable for use in pre-hospital emergency transfer, emergency department, ICU, operating room, neonatology, respiratory department and other occasions. The application population is adult, pediatric and neonate patients. The Capnograph connects with patient’ respiratory tract by the airway adapter and breathing tube.