I might just use Oscar/SleepyHead's "custom flagging" to see what might have been flagged by a PR machine under that definition that is not getting flagged by the Resmed machine.ozij wrote: ↑Sat Nov 12, 2022 12:54 amThe companies have different criteria:
Resmed:
Glossary of Sleep Apnea Terms
Hypopnea is a partial blockage of the airway (shallow breathing). During a hypopnea, breathing is reduced by 50% for 10 seconds or longer.
Philips
https://www.philips.com/c-dam/b2c/ko_KR ... report.pdf
Hypopnea(H): defined by a 40% reduction in airflow for at least 10 seconds.
But truth to tell: Even though my diagnostic sleep test showed that my untreated OSA consisted almost entirely of "hypopneas with arousal", all of the machines I've used in all modes score more OAs than Hs on a typical night. And that list of machines & modes is pretty extensive: Resmed S9 AutoSet in both CPAP and APAP modes, two PR System One BiPAP Autos in both fixed and auto BiPAP modes, a PR DreamStation BiPAP Auto in auto mode, and now a Resmed AirCurve 10 Vauto in auto mode. They all have scored more OAs than Hs for me. But on all of them, once the pressure was dialed in, the AHIs were low enough for effective treatment. I've gone back and checked the data going all the way back to 2010: On the Resmeds, a typical AHI has been between 0.5 and 1.5. On the PRs, a typical AHI has been between 1.0 and 2.5.
I think you mean to say: We know that Resmed flags more flow limitations than does Philips and responds to them rather aggressively. And I agree with that corrected statement.We know that Respironics flags more flow limitations than does Philips and responds to them rather aggressively.
The Resmed's aggressive response to increasing pressure in response to flow limitations was one of the reasons I was worried about switching to an AirCurve. I've experimented with increasing the max pressure setting on my PR DreamStation in the past since I often have a median IPAP = 9 on that machine (while the EPAP is often still at 4 cm). Every time I've opened the Max IPAP setting up to something higher than 9, the PR Search algorithm together with flow limitations that the PR machine does score leads to me using pretty close to the max IPAP setting for long periods of the night, but there is no reduction in my AHI (sometimes there is an increase in the AHI) and there is a noticeable deterioration in how I feel when I wake up and function during the daytime when I allow IPAP to get above 9cm. A lot of that deterioration in "how do I feel" is due to increased aerophagia when I increase the Max IPAP setting.
In other words, for me there seems to be a point of diminishing returns when it comes to increasing IPAP pressure in an effort to eliminate flow reductions. If the IPAP is allowed to go to 10cm or above, it doesn't really eliminate many more flow reductions and it does cause more overall problems due to waking up with aerophagia. And it can, bizarrely, increase the number of OAs that get scored in my data.