jnk wrote:... I was hoping to see where you would put the frame and just how you were going to stretch the canvas.
I was initially hoping to go with a very little, minimally time-impacting canvas.
jnk wrote:I hope I didn't derail. Once you have time, I'd like to read more of your thoughts on carbonman's charts.
No you didn't. But you should also know that waving very good rhetorical questions in front of the cpaptalk crowd is like waving highballs down at the local AA meeting. I sure don't have the will power to
not discuss those excellent questions.
jnk wrote: Because, to my mind, the autos these days seem to be more about reacting to the precursors than they are about reacting to the events themselves. Am I wrong on that?
Yes, on that note think of snore and flow limitation being A10 precursors to work with above 10 cm. Now think of snore, flow limitation, hypopneas, and apneas being four precursors a different algorithm chooses to signal-process and respond above 10 cm.
That's right about apneas and hypopneas being responded to as if they were precursors (which they are) to yet
other pending apneas and hypopneas above 10 cm. Now think about Mar's response to A10, which will only work with snore and flow signal above 10 cm. There
was no A10 response above 10 cm. But you succinctly pointed out that the AASM feels that APAP should be contraindicated for snoreless patients (including but not limited to UPPP cases).
Interestingly none of the manufacturers contraindicate APAP for UPPP. Probably because many, like Koppy, snore after sixth months or longer. But also because CPAP tends to work. But let's look at Mar's xPAP predicament. Her A10 algorithm had no snore or flow limitation signals to work with above 10 cm. That reduced her to running CPAP. But alas, she seems to need more straight pressure to consistently address her residual apneas and hypopneas than her poor LES closure can handle.
So under those circumstances, do we think it is plausible to consider what an APAP algorithm can do for her that can : 1) work with apnea and hypoponea signals above 10 cm, 2) may effectively address a good portion of the residual apneas and hypopneas at the expense of some minority of preliminary ones, while 3) keeping her mean pressure down, on average, throughout the night for the sake of pressurized air breeches through the LES.
Also, the question about whether it made any point at all to graphically demonstrate A10 not responding to A and H above 10 cm for lack of FL and snore in Mar's UPPP case. It absolutely makes sense to understand any and all failures. That's what we have done for other algorithms as well. We come around to understanding them so that we know why they do and why they don't work. Some patients who have never had UPPP will present prolific snore and FL signals, and others are guaranteed to fall short. I think the general rule in physiology is to expect bell-curve gradients. So for quite a few of us, this message board has been all about carefully looking at the details of algorithms.
Jeff, your rhetorical questions sure
never sound pompous to me. But they are often very stimulating and very compelling IMHO.
