Triggering With Intentional Leak Circuits; Cycling With Intentional Leak Circuits - ResMed Astral Series Clinical Manual

Ventilation modes

Triggering with intentional leak circuits

When using a circuit with intentional leak, estimation of the patient respiratory flow is enhanced by
ResMed's automatic leak management feature—Vsync.
Vsync technology allows the device to estimate the patient respiratory flow in the presence of
unintentional leak. Using the respiratory flow signal, the device is able to trigger and cycle closely with
the patient's effort.
The Astral device has five trigger sensitivity levels (Very Low to Very High). The higher the sensitivity
selected the smaller the patient effort required to trigger inspiration.

Cycling with intentional leak circuits

The Astral device is able to detect a decrease in patient respiratory flow during inspiration, indicating the
optimum point to commence exhalation.
The Astral device provides an adjustable cycle sensitivity set point expressed as a percentage of the
maximum flow. The higher the sensitivity selected, the smaller the reduction in inspiratory flow to cycle
to expiration.
Note: Cycling is constrained within the limits of TiMin and TiMax. This means that the inspiratory period cannot be
less that TiMin or longer than TiMax.
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