(10-01-2012, 11:23 PM)REMember Wrote: Many thanks, sleepster! ResMed it is then.
I think the S9 VPAP-Auto is much better than an S9 VPAP-S. I think the S in VPAP-S stands for synchronous, because the machine tries to respond and synchronize its two pressure levels (inhale pressure IPAP and exhale pressure EPAP) with your natural breathing. But the VPAP-S has only two fixed (manually-adjusted) levels to choose from. The S9 VPAP-Auto, on the other hand, can be set to either therapy mode, VPAP-S mode or VPAP-Auto mode.
The S9 VPAP-Auto when operating in Auto mode is like the S9 Autoset. It can be set to a range (maximum IPAP and minimum EPAP) and it will automatically adjust itself within the limits to eliminate obstructive events (flow limitations, etc). The main difference between the S9 Autoset and the S9 VPAP Auto is the AutoSet has EPR which can be manually adjusted to give up to 3 cm H2O pressure difference between IPAP and EPAP, whereas the VPAP-Auto can be manually adjusted for up to 10 cm H2O difference between IPAP and EPAP. Also, the VPAP series has many additional adjustable parameters, such as how sensitive (how quick) you want it to be when deciding you are changing from IPAP to EPAP and back. The ResMed web site says the VPAP-Auto is the optimal machine for treating only obstructive apneas (as opposed to both obstructive and central apneas, which is when a machine like the VPAP-ST or the VPAP-Adapt SV or their Respironics equivalents may be needed).
The S9 VPAP-ST is like the VPAP-S but adds a fixed (manually-adjusted) back-up breathing rate which will kick in if your central nervous systems fails to try to breathe, even though there is no obstruction. But while the VPVP-ST is forcing you to breathe at least a little, it does not necessarily maintain enough tidal air flow though your lungs to actually keep your oxygen levels adequate. Tidal flow is the in-out airflow calculated to be going through your lungs, after taking into account both estimated intentional leakage and estimated unintentional leakage.
The S9 VPAP-Adapt SV is not limited to a fixed (manually-adjusted) difference between IPAP and EPAP. I think the VPAP-Adapt SV will operate a lot like the VPAP-Auto when you are breathing on your own, and when the machine needs to force you to breathe because your central nervous system is failing to try to breathe, it will look at your tidal air flow and will automatically adjust IPAP and EPAP to maintain a steady and adequate level of tidal air flow through your lungs, to keep your oxygen levels adequate. But of course everyone is different and the S9 VPAP Adapt SV does not work out for some who try it.