TheSeatUnidirectionalValveisusedtoadjusttheairflowinthebreathingsystemcircuit.Ithastwobreathingcircuitmodules—CircleandBain/MaplesonD.Eachbreathingcircuithandlesfreshgas,recirculation,andexhaustflowdifferently.TheBag/Ventswitchclosestheventilatorpath(B). spiratorycheckvalve)tothepatient.TheBag/Ventswitchkeepstheventilatorpathclosed(B).Gasflowsfromthepatientthroughaunidirectionalvalve(expiratorycheckvalve)andintothebagarm.ThisvalveisusedinmanymedicalsystemssuchasMSCARESCAPE™MonitorB450,ARCCarestation600,ARCiVent201,ARCAespireView, XROptimaXR220amx,Aespire7100,AisysCS2etc.,