Clinical anesthetic machine is through mechanical circuit to deliver anesthetic to patient's alveolus, form anesthetic gas partial pressure, diffuse to blood, produce inhibition to central nervous system directly, and then produce a general anesthetic effect. Anesthetic patients are temporarily organism unconscious in whole or in part for surgical treatment. With the development of modern pharmacology, the progress of science and technology, especially the application of electronic computer technology, the level of modern inhalation anesthesia has been greatly improved. Inhalation anesthesia is easy to control, safe and effective, and it is the first choice in hospital operation. Modern inhalation anesthesia machine can be divided into air anesthesia machine, direct-flow anesthesia machine and circulation-closed anesthesia machine. According to the principle, the structure of modern inhalation anesthesia machine can be divided into: gas supply and delivery system, anesthetic gas volatile tank, respiratory loop, anesthesia ventilator, safety monitoring system and residual gas removal system.

The safety monitoring system is equipped with microcomputer to process and display all data, and equipped with alarm device system. Monitoring functions of respiration, circulation, nerve and muscle, can be realized, greatly improved the quality of clinical use of anesthesia and the safety of patients, and improved the success rate of surgery. The safety monitoring system includes: insufficient oxygen supply alarm, insufficient oxygen supply/interrupt laughing gas cut-off device, capacity and concentration monitoring part and malfunction alarm. The monitoring part mainly includes: inhaled oxygen concentration, exhaled tidal gas volume, airway pressure, minute ventilation volume, end-tidal CO2 concentration, anesthetic gas concentration. Therefore all kind of sensors for concentration and flow are acting very critical roles in safety monitoring system.

Based on more than 17 years’ experience on gas sensor innovation, Cubic has developed ultrasonic oxygen sensors and NDIR mainstream end-tidal CO2 sensor which have been used in anesthetic applications. Besides, in the basis of ultrasonic technology, Cubic has also innovatively develop sensing solution for different anesthesia gases measurement in anesthesia machine. All these sensors have great performances and can meet the requirement of safety monitoring system in modern inhalation anesthesia machine.