Jeff, all is good!
Sorry I worded my post in a way that made you feel an apology was necessary. So I apologize for THAT!
Here's my dirty little secret: I presently miss the vast majority of posts. So I didn't realize people were STILL trying to steer newcomers away from the Resmed APAP algorithm if those newcomers happen to have apneas above 10 cm. None of the white papers we have discussed to date support dissuading people away from the Resmed algorithm for that reason. The Resmed algorithm tends to perform
very well for patients with apneas both above and below 10cm.
There's no doubt the Resmed A10 design is
extremely counterintuitive to many laypersons. It's so counterintuitive that anyone who favors common sense while neglecting or failing to grasp empirical studies, just may continue doling out that same unsubstantiated common-sense advice.
I am very sorry about the frustration.
And I can definitely understand it. But I don't think the solution to dealing with any misinformed opinion is to offset that problem by suppressing truthful details that come up in conversation----such as how A10 uses an apnea event as a control-logic trigger event both below and above 10cm. Rather, I think the best way to deal with misinformation is with correct information.
If that counteractive process of providing the correct information seems too repetitive or cumbersome, then perhaps A10 facts, citations, and even caveats (regarding counterintuition) deserves a FAQ under the yellow light bulb up top. As a side note, that counterintuitive A10 design, that so many will continue to fail to grasp, is a testament to an equally counterintuitive brilliant mind IMHO. Berthon-Jones creatively stitched together epidemiology-based event detection with epidemiology-based probability outcomes in a way that continues to work superbly.
And I agree with the essence of Bill Bolton's comment---that ineveitable tweaks and improvements have likely been incorporated all along. However, if/when Resmed control-logic used apnea events as control-logic trigger events above 10cm, then I personally can't see Resmed calling that new algorithm "A10"---since that 10cm statistical demarcation will no longer be employed.
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ozij wrote:As I noted in my previous post::
In response to a Hypopnea FAQ Resmed wrote:How do the AutoSet devices handle hypopnea events?
AutoSet devices respond to obstructive hypopnea events when they are associated with flow limitation or snoring. Hypopneas that are central in origin (related to your central nervous system, not physical obstruction) should not be treated with increased pressure.
However, Resmed in describing its algorithm is very consistent in not describing a (ResMed defined) hypopnea on its own as a reason for raising pressure.
The issue of whether Resmed responds to hypopneas: my own opinion is that Resmed will respond to "wave flattening" (or "flow limitations") that are superimposed on hypopneas---and Resmed will respond to "wave flattening" that just so happens to be unaccompanied by hypopneas. Resmed will thus respond to: 1) apneas, 2) snores, and 3) flattened waves (whether or not they are concomitant with hypopneas).
In both cases Resmed is increasing pressure in response to flow limitations. However, in that first case, obstructive hypopneas receive an incidental and beneficial pressure response as Resmed takes aim at the flow limitation instead of the hypopnea (one of Resmed's "three lines of defense").
Resmed will never increase pressure in response to a perfectly rounded hypopnea---which is probably central and assumed normal more often than not by Resmed. Back when Berthon-Jones performed the interview that ozij linked to, some members of the blossoming and standards-shy sleep industry tended to refer to apneas, hypopneas
and wave flattening as a "flow limitations" super-category, if you may. Depending on which scientist or researcher you happened to be reading back then, the terms weren't always the same---for lack of standardization.
Anyway, I suspect Berthon-Jones thought of central hypopneas simply as hypopneas. And I think he also thought of any wave-flattened volume or amplitude reduction---short of a frank apnea---as a flow limitation because of that wave flattening. To this day it's wave-flattening, snore, and apneas that Resmed employs as their three lines of defense. And when a hypopnea occurs along with that wave flattening, then I think that accompanying obstructive hypopnea gets a pressure response---but
if and only if that accompanying flattened wave happens to present its own sufficient criteria. That hints that not all obstructive hypponeas may receive a pressure response---if that concomitant wave-flattening detection criteria falls even slightly short.
So there you have one possible control-logic scenario that manages to fit all of Resmed's above statements about hypopneas and their three lines of defense.
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rested gal wrote:Crazy people...
...I'm on a messsage board with crazy people.
And I love it!
Whew!
If you like crazy people, then you've come to the right place...
, I do like the ability to adjust pressure at .2cm increments. 
