Exploration and Improvement of End-tidal Carbon Dioxide Verification Device for Multi-parameter Monitor
The curve monitoring of end-breath carbon dioxide(ETCO2)module has the function of monitoring ventilation and reflecting circulation,and is one of the important monitoring indexes for anesthesia surgery,respirato-ry and critical patients.When the standard atmospheric pressure is 760mmHg,the normal value of ETCO2 is 38mmHg,but when it exceeds 45mmHg,it will indicate insufficient ventilation.Therefore,in order to meet the de-tection requirements,different concentrations of CO2 need to be prepared.In this paper,the existing verification de-vices in China can not relieve pressure in time when the gas solenoid valve is closed,resulting in gas backflow and affecting the concentration of the valve port.The results show that the improved gas piping system can ensure the stability of CO2 concentration and flow rate.