Confusing ResMed AirCurve Specifications

I'm trying to pick a new bilevel apnea machine, but am confused by the specs called out in the table at the bottom of the following page:

http://www.resmed.com/us/en/consumer/products/devices/aircurve-10-asv.html

Anyone know what the following features mean for a bilevel autoadjusting apnea machine?

S T ST Trigger and cycle

The manuals seem to describe the other specs in the table at the bottom of the page.

Thanks for any info, Chris

Hi Chris. The S is for spontaneous, and it means that the patient's breathing is what causes the machine to cycle between the inhalation and exhalation pressures (IPAP and EPAP). T is for timed, and the machine will "trigger" the patient to take a breath at certain times based on the machine settings. ST is for spontaneous timed, and this machine will monitor the patients breathing and respond to the inhalation and exhalation (like the S), but it will also trigger the patient to breathe if it does not detect breathing. Trigger and cycle settings can be used by clinicians to help better adjust the machine to a patient's breathing and help keep the machine in sync with breathing. Hope this helps!