基于往复式柱塞的呼吸机测试仪校准装置仿真

Simulation of Ventilator Tester Calibration Device Based on Reciprocating Piston

呼吸机作为治疗重症新冠肺炎等呼吸疾病的重要医疗器械,需要使用呼吸机测试仪进行定期校准。针对目前有关呼吸机测试仪的校准工作效率和精度低,且动态流量等参数缺乏科学的评价依据等问题,提出了一种基于往复式柱塞的动态流量发生装置,通过伺服电机驱动柱塞缸往复运动,产生频率幅值可调节的动态流量。通过AMESim一维仿真获得动态流量与柱塞速度的关系曲线,并利用ANSYS Fluent三维动网格技术对所得柱塞速度下输出流量进行仿真验证。初步结果表明装置可以输出频率约0.4 Hz,潮气量最大为2876 mL,流量幅值为240.92 L/min的动态流量,以及流量幅值196.43 L/min,误差2.5%左右的静态流量,可以实现静态、动态流量整合校准,满足呼吸机测试仪流量参数的校准需求。

As important medical devices for treating respiratory diseases such as COVID-19,ventilators need to be calibrated regularly by ventilator testers,but at present,the calibration efficiency and accuracy of ventilators tester are low,and parameters such as dynamic flow rate are lack of scientific evaluation basis.A dynamic flow generation device based on reciprocating piston was proposed.The reciprocating movement of piston cylinder was driven by servo motor to generate dynamic flow with adjustable frequency amplitude.The relationship between dynamic flow and piston velocity was obtained by AMESim 1D simulation,and the output flow rate at the obtained piston velocity was verified by using ANSYS Fluent 3D dynamic mesh technique.The preliminary results show that the device can output dynamic flow of 240.92 L/min with about 0.4 Hz and the maximum tidal volume of 2876 mL,and static flow rate of 196.43 L/min and error about 2.5%,which can realize the integrated calibration of static and dynamic flow rate and meet the calibration requirements of the flow rate parameters of the ventilator tester.