Curious about Encore Viewer graphs ...

dand · Post by **dand** » Thu Oct 25, 2007 6:23 am

http://docs.google.com/Doc?id=dghh2t92_14fmrzm8

The link above takes you to a slice of two Encore Daily Details graphs. The one on top is pressure vs time. The one on bottom is sleep disturbances vs time. You can't tell from this slice, but my M-series Auto is set for a min of 6 and a max of 11. Cflex = 2. I have two questions:

1. What caused the nine little pressure spikes between about 2 and 3.5? I had thought that apap pressure changes in response to apneas and hypopneas, but as you can see, there are very few of those occurring during that time span. Yet, the pressure keeps jumping up and down. I see these little guys a lot on my Daily Details graphs. Any ideas why this is happening? (You can't see the leak graph in the slice, but it is quite flat and low during this time frame. So, I'm pretty sure leak is not an issue here.)

2. Also, between 3.5 and 3.8, I was wide awake and breathing normally. Why did my machine think I was having apneas and hypopneas? Has anyone else observed this phenomenon?

Any info on this is appreciated!

dand

DreamStalker · Post by **DreamStalker** » Thu Oct 25, 2007 8:11 am

dand wrote:http://docs.google.com/Doc?id=dghh2t92_14fmrzm8

The link above takes you to a slice of two Encore Daily Details graphs. The one on top is pressure vs time. The one on bottom is sleep disturbances vs time. You can't tell from this slice, but my M-series Auto is set for a min of 6 and a max of 11. Cflex = 2. I have two questions:

1. What caused the nine little pressure spikes between about 2 and 3.5? I had thought that apap pressure changes in response to apneas and hypopneas, but as you can see, there are very few of those occurring during that time span. Yet, the pressure keeps jumping up and down. I see these little guys a lot on my Daily Details graphs. Any ideas why this is happening? (You can't see the leak graph in the slice, but it is quite flat and low during this time frame. So, I'm pretty sure leak is not an issue here.)

2. Also, between 3.5 and 3.8, I was wide awake and breathing normally. Why did my machine think I was having apneas and hypopneas? Has anyone else observed this phenomenon?

Any info on this is appreciated!

dand

It happens on mine. I think that is the way the Respironics auto algorithm works ... periodically checking. Rested Gal or Snoredog will probably drop in and post a better explanation.

dand · Post by **dand** » Fri Oct 26, 2007 9:19 am

Thanks DreamStalker for your input. Yes, I had suspected it might have something to do with the algorithm. I tried searching for an explanation of the algorithm but couldn't find much. I also thought of the possibility that some sleep disturbances are causing those little peaks and that maybe those disturbances are so minor that they don't show up on the sleep disturbance graph.

Here's another question I'd like to add to the other two questions:

3. What is Flow Limitation? I think I understand Apneas and Hypopneas, but how does Flow Limitation fit into the picture as far as my M-series Auto interprets such things. These days I'm not getting too many Apneas, but I'm still getting a fair number of Hypopneas and a few Flow Limitations. I gather from reading other posts that Apneas are worse than Hypopneas; how do they compare with Flow Limitations?

I might explain that I've been using the APAP for about a month. Only after switching to the Comfortlite II mask have I really begun to have any success and low AHI's. I'm below an AHI of 5 most nights and most of that is hypopneas.

Thanks,

dand

ozij · Post by **ozij** » Fri Oct 26, 2007 9:54 am

"Understanding Sleep Disordered Breathing"

By Resmed - great explanation and examples - needs flash player, takes time to download - and is excellent.

Make sure to have sound on.

O.

rested gal · Post by **rested gal** » Fri Oct 26, 2007 10:21 am

I think of an hypopnea as a baby apnea.

I think of a flow limitation as a baby hypopnea.

Actually, I guess technically all of them are flow limitations...some being much more limited air flow than the others.

As I understand it, an obstructive apnea doesn't have to be a complete full closure. I don't remember the exact percentage, but it's something like if your breathing shows you're getting less than 20% (air flow as measured by the machine) it's counted as an apnea.

Or something like that.

WxMan · Post by **WxMan** » Fri Oct 26, 2007 10:42 am

I've got the same machine and see the same thing on the EncorePro data...little blips separated equally by time which resemble leftward facing chairs. Seem to occur about every 10 minutes when the machine is not responding to actual events. For that reason, I've always assumed that it was related to the machines algorithm...it's just checking to make sure all is OK.

The pressure runup while first going to bed occurs nearly everytime I initially go to bed. Understand that any data from the machine while awake is suspect. The machine is designed to interpret the "automatic" type breating data that occures while asleep. Pattern is too variable while awake for the machine to interpret for many...and I'm one of them due to shallow breathing.

I habitually now use the ramp when going to bed....to dampen this pressure runup effect.

RosemaryB · Post by **RosemaryB** » Fri Oct 26, 2007 6:53 pm

[quote="ozij"]"Understanding Sleep Disordered Breathing"

By Resmed - great explanation and examples - needs flash player, takes time to download - and is excellent.

Make sure to have sound on.

O.

wabmorgan · Post by **wabmorgan** » Fri Oct 26, 2007 10:04 pm

WOW!!!! That is a VERY GOOD video.

Shows that even just snoring isn't good.

I think more people should see this!!!!!!

Guest · Post by **Guest** » Sat Oct 27, 2007 9:56 am

I'm also impressed with that video. Thanks, Ozij. I've emailed it to all my friends. I wonder just how prevalent OSA is? How often is it misdiagnosed or just not treated at all? My own family physician looked into everything else to explain my fatigue. I requested a reference to a sleep doctor. But my sleep test was flawed. I just couldn't sleep much in the lab. So, the original titrated pressure that came out of the study was ineffective. Only after acquiring an APAP machine and looking at the data from Encore did I finally get a grip on the problem.

WxMan, I think you're right about the algorithm. I wish I could find a more detailed description of the algorithm. Anyway, it's good to know others have the same things happening in their graphs. Yeah, ramping is probably the best way to avoid those false apneas in the "pressure runup effect," as you coined it.

dand · Post by **dand** » Sat Oct 27, 2007 10:00 am

Hmmm. When I submitted the above comments, it was posted under "Guest." I'm pretty sure I had logged in. Anyway, I'm hoping this post will show up as "dand"!!!

Mask