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Dreamstation Central Apnea detection - Printable Version

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Dreamstation Central Apnea detection - sleepyp - 01-13-2020

Can anyone comment on the Dreamstation's Central Apnea detection algorithm?

In my sleep study no centrals or obstructive apnea events were detected.
I had an AHI of 29.1 of all hypopneas, with AHI during REM of over 40. The study didn't seem to measures RERAs or Flow Limits. Oxygen desaturations went as low as 86%. I had bad daytime sleepiness and was even falling asleep during my favourite football team's games.

Since starting treatment on a Dreamstation Go 3 months (8-20cmH2O and various pressure setting experiments, tried all Flex settings including off) the APAP has consistently been raising pressure to treat apneas it was detecting.
Pressures were frequently getting to 16cmH20+. It was showing almost all apneas and centrals, the apneas appearing to be what drove the pressure up.

On saturday I received a Resmed Autoset 10.
Since using it (@ 8-20cmH2O, EPR3) the highest pressure has been 10.3, and it sits mainly at 8.3 as an average.
My hypopnea index average has been 0.25 for the three nights.
No obstructive apneas have been detected for three nights, just like my sleep study.
I've been feeling great the last three days, as opposed to how I felt with the Dreamstation Go.
I have been having centrals of around 3 per hour. I think this might be because I'm using EPR at 3 and I'm not used to this level of ventilation, my Tidal Volume has increased quite a bit.

My questions:
1. Is the Resmed better at detecting Centrals? It seems like the Dreamstation was detecting many (treatment emergent in my case) Centrals as Apneas and ramping the pressure. Remember, my sleep study found no centrals or apneas, and neither has the Resmed machine since I've started using it. **
2. Is EPR significantly better than Flex at dealing with RERAs/Hypopneas/Flow Limits? It certainly seems to be the case for me. Why would that be? The Resmed also seems to detect Flow Limits and reacts very quickly, whereas the Dreamstation Go didn't seem even detect Flow Limits.
3. Am I imagining all of this? :-)

** From what I can see the Dreamstation uses a single pulse to determine Apnea vs Central. These pulses are not used for every event and it seems to mark non breathing events without a pressure pulse as Obstructive. It then drives the pressure up causing even more Centrals and (potentially incorrectly detected) Apneas.
The Resmed appears to use some kind of oscillation for every non breathing event, and it marked all of mine as Central and not raised the pressure.


RE: Dreamstation Central Apnea detection - sleepyp - 01-14-2020

Is it possible that higher pressures (greater than 11) and/or increased leaks make it difficult for the machines to accurately determine centrals vs apneas?
Other than brand of machine, that's the only other difference I can find.
The Dreamstation would go up to 18 chasing apneas, whereas the Resmed hasn't gone over 10.3 yet.


RE: Dreamstation Central Apnea detection - sleepyp - 01-15-2020

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Some OSCAR screengrabs for reference.