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+--- Thread: Couple of questions about RERAs (/Thread-Couple-of-questions-about-RERAs)
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RE: Couple of questions about RERAs - SnoringInOregon - 10-05-2017
(10-04-2017, 02:59 PM)Mistertransistor Wrote: Thanks again OpalRose. Here's a link to an example of a RERA which I don't understand
http://wylie.org.uk/RERA.png (that's my web site)
can you see why the machine says I have respiratory problems there?
The Dreamstation reports a duration associated with an RERA. Sometimes that duration can be longer than 1 minute. You have zoomed in so much here, that the end of the RERA may be off to the right of the chart.
Which brings up another issue. When you hover your cursor near the RERA event, SleepyHead highlights the duration. IMO (at least in some circumstances) it gets it wrong. I believe that the tick mark on the chart is best interpreted as the start (or perhaps the middle?) of the RERA, but not as the end of the RERA.
Unfortunately SleepyHead does it backward, it highlights backward from the tick, whereas it should be highlighting forward. Of course this may vary from machine to machine. Perhaps Resmed does it differntly, and when this highlighting was coded into SleepyHead there was a good reason to do t that way? My observations are bassed on the Dreamstation (which you also have).
These hints may help in interpreting the RERAs. But there's still subtlety involved. These events aren't as easily identified as are OAs and CAs.
Edit: I have attached a zoomed in area of two RERAs which I recently had. If interpreted the way that SleepyHead currently highlights, the events overlap. This doesn't make sense. If we interpret that second event as starting at the tick, then it makes much more sense. You can easily see how breathing improves 60 seconds after the tick.
RE: Couple of questions about RERAs - Walla Walla - 10-05-2017
The following is from Beginners Guide to SleepyHead. Hope it helps somewhat. :
"Since a RERA requires an EEG arousal to be scored and there is NOT a clear definition of how much the flow rate must be reduced for a RERA to be scored, most CPAP machines do not attempt to flag RERAs. But Philips Respironics has developed a proprietary algorithm for scoring what it believes are RERAs. Since there is no EEG data, the Philips Respironics RERA algorithm is based on a statistical analysis of what the wave flow for real RERAs on PSGs looks like: Loosely, the Philips Respironics RERA algorithm looks for evidence of increasing respiratory effort (i.e. "flow limited breathing") followed by one or more "recovery" breaths. When we look at the RERAs scored in our sample patient's data, it's sometimes difficult or impossible to see both the "evidence for increasing respiratory effort" and the "recovery breaths". We've also noticed that the placement of the RERA tick mark is far less consistent: Sometimes it appears at the beginning of the RERA, sometimes it appears at the end, and sometimes it appears in the middle. But every now and then we see a RERA where it is easy to see why it was scored."