ResMed Elisee 150 Clinical Manual page 53

P
Patient triggering of
an assisted controlled cycle
T mecha
Figure 4.22: Operation of SIMV mode.
Note: In zone 1, the patient can trigger only assisted controlled cycles (ACC), and only within the
synchronisation window (Wsync).
Depending on the respiratory rate and the I/E ratio settings, if the expiratory time is less than the
length of the Wsync (5s or 1.5s), the Wsync will last for the whole of the expiratory phase. The
patient will not be able to trigger cycles of spontaneous ventilation with pressure support
between controlled cycles (PS).
P
1.2 s
Figure 4.23: SIMV mode.
Note: In adult ventilation for example, it is important to use this mode with a respiratory rate of
less than 10 bpm if you want to keep a window for triggering spontaneous ventilation with
pressure support (W
At that respiratory rate, the cycle time is 6s (60/10). If you set a Ti of 1.2 s, the Te will be 4.8s.
This means that Te < 5s (Wsync) and so the WVS value is zero.
With a respiratory rate of 8bpm and an inspiratory time of 1.2s, the Te will be 6.3s, leaving
1.30s available for the W
NOT013189-6
Device controlled
cycle
Zone 2
Zone 1
T exp
ΔT ΔT
T mecha
Wvs: Window for the triggering of spontaneous PS cycles
Wsync: Window for the triggering of assisted controlled cycles (5 or 1.5 s)
T mecha: Device period defined by the frequency
4.8 s
Wsync: Window for the triggering of assisted controlled cycles (5 or 1.5 s)
T mecha: Device period defined by the frequency
).
VS
.
VS
Triggering of a Support
cycle by the patient
Zone 3
T mecha T mecha
t
t
Ventilation 53/170