GE Datex-Ohmeda Aisys Carestation Reference Manual page 86

Aisys
Mechanical expiration
(EZchange and
condenser
OFF)
D
6
6
AP Airway Pressure
D Drive gas
FG Fresh Gas
SGR Sample Gas Return
4
Expiratory flow
5
Flow to bellows
6 To scavenging
Figure 2-41 • Mechanical expiration with EZchange Canister and Condenser OFF
2-54
Drive-gas flow stops and the exhalation valve opens. Exhaled gas flows from the
patient (4), through a unidirectional valve (expiratory check valve) and into the bellows
(5). Residual drive gas (D) flows out of the bellows to the scavenging system (6).
If PEEP is selected, static pressure on the pilot port of the exhalation valve sets the
PEEP level.
During exhalation, fresh gas flows backwards through the EZchange module (FG) into
the expiratory limb, downstream of the expiratory check valve.
For machines that are plumbed to return sample gas to the breathing system, the
returned gas (SGR) enters the breathing system after the expiratory check valve.
5
5
AP
FG
SGR
FG
4
04/08 M1046983