Clinical menu only allows 4-20cm. Service software allows you to set a minimum ramp start pressure as low as 1cm for pediatric patients, or a specific ramp pressure shape (linear vs. exponential).
: Most modern ResMed devices (like the AirSense 10 and 11) receive "Over-the-Air" (OTA) updates automatically. You do not need to download service software to keep your machine's firmware current. How to Get Technical Assistance