title: [Functional analysis of the smart vent compensation system and the fresh gas decoupling system].
abstract: BACKGROUND
  In MIPPV mode, an anesthetic machine supplies a fixed amount of tidal volume (TV) corresponding to changes of fresh gas flow (FGF) in a certain period of time. In this research, we examined discrepancy of delivered TV and preset TV, after a change of FGF in both fresh gas decoupling system (FGDS) and smart vent compensation system(SVCS).
  
  
  METHODS
  FGF value was changed from 0.1 l x min(-1) to 12 l min(-1), and after 10 times of ventilation, we measured TV and peak pressure of inspiratory circuit pressure(PIP).
  
  
  RESULTS
  Following a gradual FGF increase, PIP dramatically increased in FGDS. TV and PIP; however, remained unchanged in SVCS.
  
  
  CONCLUSIONS
  FDGS has a valve for closing FGF in the inspiratory phase and it makes the gas circuit over volume, but SVCS changes the volume of gas delivery to the ventilator by CPU according to FGF changes. Therefore it is assumed that the safety system of SVCS is superior to FDGS in high and low FGF.
authors.affiliation: Division of Anesthesiology, Higashi-Yamato Hospital, Tokyo 207-0014.
authors.forename: Kappei
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000776:Anesthesiology / Q000295:instrumentation*; D004869:Equipment Safety; D012122:Ventilators, Mechanical