OutaSync wrote:Wow! I think I actually understood that! I have to tell you, SWS, that you often go waaaaay over my head. I've lost too many brain cells to keep up with most of what you write. (Is it just me? ) You guys must have gotten diagnosed while you were still young.
So, you all will help me get set up when I get a new machine? And don't worry, I understand that there are no guarantees. I've come too far to quit now. A year ago, I had nights where I wasn't breathing for 40 minutes.
You all are fantastic. You may have saved another life, here.
Bev
Bev,
We have a very good range of experience here on all these types of machines & there is nothing nicer than helping someone who understands what their problem is & can follow good advice.
Re the SV machine & how it responds to AIs vs HIs vs irregular breathing.
I still get AIs & my base pressure on the machine is 11 CMs (ipap = 14) but the score is typically lower than 1.0 per night & that is better than the average population. If I ghave a cold or some other disturbance (such as a party night) I often see AIs go to 2.0 perhaps even rarely 3.0.
HIs seem nonexistent but because this machine monitors each breath and halfway through can decide the target Peak Flow isn't going to be met will boost pressure higher so I would expect HIs to be almost non-existant. For me the machine regularly boost pressure when I drop below Peak Flow target & the machine will go as high as 20 CMs with my current setting but the incredible thing is I never really notice as I am usually too happily off in dreamland. When I do wake & feel these boosts, they seem incredibly gentle & I don't seem to get the leaks I would expect with such pressure ranging. Leaks from the boosting just don't happen even if commonsense suggests they may. The same is not true with the Vpap SV. It tracks breathing so tightly that any deviation in breathing & it is all over you but its responses are not gentle like the Bipap SV's.
The Vpap SV is ideal for people with serious irregular breathing as it takes very tight control. The Bipap SV is far better for normal xPAPers who find that std CPAP & APAP just don't seem to sustain good results even if the numbers look ok. The Vpap SV I have leaks regularly when it boosts pressure. I am still trying to understand this aspect but I put it down to the Vpap SV just being to damned quick off the mark with any irregularity even if it just me turning over - whump it hits me immediately with a boost & persists, but the bipap SV lags & often by the time I come right it was just gently adding a boost thus the situation passes.
Despite any theoretical comments by others as too if the SV can deal with AIs, I find it can but my stats show that a few will often get through - just what those really are though is open to interpretation. Normally we set the epap base to deal with AIs - 10 CMs (I set my epap to 11 CMs as when I measure epap at the mask with a dial manometer it shows as 10 Cms & I have long been aware of a 1 CMs loss in a 6' hose at 11 CMs of cpap pressure at the machine). The Vpap SV doesn't need that 1 CM adjustment as it samples the pressure right at your face & is dead accurate (and thus very very tightly in control ).
Also, when anyone talks about how a timed Bilevel will boost your breathing if you fall below the timed rate (or backup rate), the ability of the machine to get you breathing again depends on what you set the epap - ipap gap to. If it is set at say 2 CMs = then the machine switching from say 11 CMs epap to 13 CMs ipap may not be enough to get you going again. The gap has to be tuned to the person and be adequate enough that when the epap-ipap switch occurs, you get the message - BREATHE- loud and clear. The downside of too big a gap is that it can trigger hyperventilation & I can demo that on myself with a 7 CMs gap. The restorative effect of the epap-ipap gap also gets diluted when people increase their rise time which many do, not realizing they are lowering the effect of the start breathing again trigger.
The Bipap SV is like any other bilevel in regard to timed mode but it has one extra trick up its sleeve. Once you have started to breath again, it will ensure you reach your Peak Flow target quickly by raising pressure enough to make it happen.
#2 Correction made here.
After doing tests last night I was able to show that the Bipap SV *will* increase Ipap pressure if it detects zero flow (a central). Each time it cycles back to ipap while trying to get you breathing, it added approx (my guess) 3 CMs pressure in my case & kept adding it each new ipap cycle until you breathe again at which time it reverts to normal tracking. I belive it will go from IpapMin to IpapMax in 3 breathing cycles (but am not 100% certain of this). The timed mode overrides the boost effect (i.e. it won't suddenly ram lots of air into you if you are in the middle of a central, but it will keep bumping up Ipap and as mentioned, within 3 cycles will take ipap to IpapMAX (on my machine that is 20 CMs)), it uses the epap-ipap-epap-ipap switching to start you breathing then once it knows you are it brings you right back to your targeted peak flow within 3 breathing cycles. My educated guess in regard to the Vpap SV, is that it tries to bring you into line within a single breathing cycle & this can be counter productive if you merely turned over in your sleep for any normal reason. The Vpap SVs quick reactions seem to foster leaks as well as arousals & many who I have spoken to who use Vpap SVs comment on not feeling they are sleeping as deeply as they would like. For me, the consistent deep dreamy sleeps started the day I used the Bipap SV. The deep dreamy sleeps turn into 'rested wakefulness' the moment I swap to the Vpap SV. The success of the Bipap SV for myself leads me to call it my 'Dream Machine'.
So AFAICT - the Bipap SV has one hell of a well designed algorithm (certainly for me) - very very well thought out and very very gentle & very very effective. This machine is what AUTOs would like to be but aren't !.
DSM
