Apnoea - ResMed S9 Elite Clinical Manual

Apnoea

The enhanced AutoSet algorithm detects both obstructive and central apnoeas. If an apnoea occurs, the
device responds appropriately.
Obstructive apnoea
An obstructive apnoea is when the upper airway becomes severely limited or completely obstructed.
AutoSet generally prevents obstructive apnoeas from occurring by responding to flow limitation and
snoring. If an obstructive apnoea occurs, the device will respond by increasing pressure.
Central apnoea
During a central apnoea, the airway will remain open, but there is no flow. When a central apnoea is
detected, the device responds appropriately by not increasing pressure.
6
Complete airway obstruction
Open unrestricted airway
Absence of flow (for at least 10 sec)
Time
Inspiratory flow-time curve
Absence of flow (for at least 10 sec)
Time
Inspiratory flow-time curve