ResMed Elisee 150 Clinical Manual page 46

Inspiratory trigger
The value which defines when an inspiratory phase is triggered. This trigger can be defined in
terms of flow or of pressure:
•
Invasive inspiratory flow trigger TgI( ): Operates with a double limb circuit only.
At the end of expiration, when the patient starts to inhale, the flow measured by the
expiratory sensor becomes lower than the flow measured by inspiratory sensor. The device
triggers an inspiratory phase when the difference between the flow measurements reaches
the set trigger value. The flow trigger is recommended for situations which require a very
sensitive trigger level.
•
Invasive inspiratory pressure trigger TgI(P): Operates with a single or double limb circuit.
A depression in the respiratory circuit during the expiratory phase triggers the inspiratory
phase when the set trigger value is reached.
P
Figure 4.15: Invasive inspiratory triggers.
•
Non-invasive inspiratory trigger TgI: Operates with a single or double limb circuit.
It operates according to the amplitude of the pressure variation when a patient inhales.
The operation of the trigger is based on an algorithm that analyses the differences in
expiratory pressure every 10ms, enabling detection of rapid and slow patient breathing.
The trigger also takes account of leaks in the circuit.
The most sensitive trigger value is 1.
P
Figure 4.16: Non invasive inspiratory trigger.
46/170
TgI
V
TgI = 1
TgI = 2
TgI = 3
Tgl = 4
t
t
NOT013189-6