AF, OSA, CA, PLM & PAP experiments...

[sheepless]

I agree asv appears to be a sensible conclusion, but I wonder how many of your events are triggered by plm. no machine will help plm and some may actually hinder sound sleep in responding to plm induced flow limitations.

treating the plm first might reduce your events enough to make asv unnecessary. easier and cheaper than working the system to get asv.

[kappa]

Saw a sleep specialist today. He was surprisingly willing to look at some of my OSCAR charts, including my leg movement studies, but didn't seem keen to put too much weight on that data - not unexpected since I'm unknown to him and the data is using a novel approach and unlike what they deal with in lab studies.

So we're off for an inpatient lab titration study to find optimal mask, pressure settings, etc.

He was rather dismissive of the presence of central and mixed apneas in the original home based study (which he wasn't involved with and only had the printed report from), suggesting that the centrals are associated with sleep->wake transition (although many are not). He didn't think the PLM was excessive and clearly wants people he trusts using known methods to look at this as part of the titration study (which is reasonable). 

He seemed to think that leg movements were more likely part of the arousal process rather than a trigger for hyperventilation->hypocapnia->central apnea, but my data clearly shows that the leg movement happens simultaneously (within half a second) with the change in respiration. e.g.
   

So we'll see where this takes us... hopefully we can get to the bottom of this...

[Sleeprider]

The earlier CA events have given way to a pretty clear obstruction. I think you need to get your minimum pressure up to about 8.5 and things are going to stabilize.

[kappa]

The earlier CA events have given way to a pretty clear obstruction. I think you need to get your minimum pressure up to about 8.5 and things are going to stabilize.

Hi Sleeprider. Not sure what you are looking at to see obstruction here. In this last screenshot I think that both apneas are clear airway events - you can see significant flow in response to the pressure pulse plus there is fluctuation that looks like a pulmonary pulse that disappears in a true obstructive event (e.g. see the rightmost event in the image that jaswilliams quoted in the 07-07-2020 post where it starts as a central and then becomes obstructive and the pressure pulse response disappears as well as the pulmonary pulse). i.e. clear in blue circle, obstructed in red:
   

[kappa]

I've been experimenting with measuring my leg movement and here's some results from last night where I tried a higher pressure. It was rather unpleasant and leg movements ("Inclination" graph) increased with PAP apart from a few windows (23:00-23:25, 23:32-23:45, 00:38-01:01). I gave up and went stopped PAP at 2:30 but there were still quite a few leg moments and position changes ("Orientation") even then:


Even in a half awake state I was having major leg twitches every 20-40 seconds...

Here are some zooms of the period of stable sleep leading into movement (movement and flow synchronized to within around 0.5s)...
               

Do these flow graphs show limitation? Clearly there's large inhale and/or exhale concurrent with the leg movement...

[sheepless]

looks flow limited to me, leading to the event and after the large inhales: flatish, slanted, jagged inspiration tops and/or lower volume. do you see this flow rate pattern repeat, I assume every 20 to 40 seconds? do they come in episodes from brief to an hour or more? mine are usually 10 -20 seconds apart. I find the periodicity is most visible in a 7-10 minute view scale.

[kappa]

Hi Sheepless,

My movements are typically 20-60 seconds apart, and yes, minutes to an hour or so (if you count a break of ~3 minutes as the end of an episode).

I switched the machine to A-Flex level 2 last night rather than no Flex and the OA events went away (pretty sure most were misclassified anyway). No real change in leg movements and I don't really feel any more rested.

   

Here's a 10 minute zoom of a leg movement period...
   

And a 2 minute zoom within that. The flow is a little strange,... due to A-Flex? I'll give C-Flex a try next...
   

[kappa]

So I tried last night with C-Flex. Seemed a lot more natural (more like EPR on the ResMed) whereas A-Flex feels a lot more bursty at the start of inhalation (from what I've read A-Flex has pressure changes in both exhale and inhale which I find quite irritating).

I was wearing a soft collar (which I have had on most nights, although I find it gets a bit hot) and there doesn't seem too much difference from previous nights in terms of leg movement starting after an hour or so (sleep phase related?). I woke at around 3 and didn't really sleep until I switched the machine off...


Some of the flow patterns look strange though...
Few leg movements leading in to "OA" - exhales seem brief followed by small inhale - C-Flex pressure changes driven?:
   

[Damiansd]

Where did you get the accelerometer from? I'd be keen to get one of those.

[kappa]

Where did you get the accelerometer from? I'd be keen to get one of those.

Hi Damian.

I picked it up from Amazon AU, it's also available in other geos. The unit I have is a WitMotion WT901BLECL which I showed in this thread. The original unit I got had some issues with continuity in the Y-axis but they sent me a new one which has no issues (and also is USB-C) as well as a USB BLE 5.0 adapter (which I'm not using since I wrote a small python app to collect the data using the bluetooth on my laptop).