NEWER VENTILATORSWHAT MAKES THEM DIFFERENT?John Newhart CRTT.RCP.PURITAN BENNETT MA-1Puritan Bennett MA-1First released August 1967.Simple to useBasic IMV system(non-sync).Bellows spirometer for exhaled gas measurement.SIEMENS 900 CSIEMENS 900 B/C900 B available in the USA early 70s.Time limited and minute volume preset.Patient or time cycled or SIMV.Expiratory flow monitoring.BEAR IBuilt in SIMV.Monitoring of tidal and minute volume.Pneumatically and electrically powered,electrically controlled
