Stats and Graphs not in sync..I think

Note the AI of 1.6 and the HI of 8.7 but the graphs show large AIs and tinh HIs.

You can also see from the graph that things changed when I went back to sleep, as I slept on my side, using the mirage activa nasal mask (for the entire night). Could the graphs be wrong or am I interpreting them incorrectly? Also, to me it looks like the leaks are terrificly controlled so why the AIs when I sleep on my side?

Alan

allend wrote: Note the AI of 1.6 and the HI of 8.7 but the graphs show large AIs and tinh HIs.

I think you're misinterpreting the meaning of AHI, AI, and HI and the numbers ResScan shows on the flags for each of the apneas it detects.

Your AHI = 1.6 means that on this night you were having an average of about 1.6 apneas EACH hour. Since your machine was on for about 8.5 hours, that means that you experienced about

(1.6 apneas per hour) * (8.5 hours) = 13.6 = 14 apneas during the whole night. (Resmed truncates decimals, so you always round up)

And when I look at the detailed data graph, I can see at least 12 red flags with numbers on the top of them. The other two are probably well hidden in the cluster of events you had between 9:00 and 10:00 AM. Each of these red flags represents a SINGLE apnea that the Resmed VPAP Auto 25 detected. The number on top of the flag indicates how long the apnea lasted. In other words, the number on the flag indicates how many seconds the VPAP Auto 25 thinks you were NOT breathing due to an obstructive apnea.

Your HI = 8.7 means that on this night you were having an average of 8.7 hypopneas EACH hour. Since your machine ran for about 8.5 hours, that means that you experienced about

(8.7 hyponpneas per hour)*(8.5 hours) = 73.94 = 74 hypopneas during the whole night.

Now each hypopnea gets a little blue square on the event graph. The VPAP Auto 25 does NOT try to determine how long the hypopnea lasted, it merely indicates that one occurred. The box is put at the END of the hypopnea, if I recall correctly. Now when I try to count the boxes, I really don't see anywhere near 70+ of them. But the thing about these hypopnea boxes is that they easily run together and that they can hide each other. To really count the hypopnea boxes, you need to change the TIME FRAME on the bottom set of graphs to something really small (five minutes at most) and scroll through the data for the entire night focusing the event graph. Each time you come to boxes that are running into each other, you need to reduce the time frame even further---you can go all the way down to 10 second intervals if you want to.

So my interpretation of your data is that SINCE the AHI number makes since (14 apneas in 8.5 hours is 14/8.5 = 1.6 apneas per hour, so AHI=1.6), there's no reason to suspect that the HI number is wrong---in the sense that your VPAP Auto 25 likely counted what it thinks were 74 hypopneas during the 8.5 hours the machine was running.

Also, to me it looks like the leaks are terrificly controlled so why the AIs when I sleep on my side?

Alan

Your leaks are "ok" but not perfect. As to why you're having so many apneas on your side, I don't know. It may be an odd occurance of this particular night or it may be that you need more pressure support on your side or it maybe something else. If you continue to regularly have clusters like you had between 9:00 and 10:00 am on this day, then you should tell the sleep doctor's office that you're worried about whether your current prescribed pressure level(s) are effectively managing your apnea.

How long have you been using your machine? If you're a real newbie, some of these issues may begin to resolve as you get more used to the machine. But if they don't, you really should let your sleep doctor know that your AHI is still well above 5.0 even though your AI is relatively low.

Hmmm, am I missing out on something? I don't have the Respiratory Rate on my ResScan stats - guess I'll have to take a look when I get home for where to find this.....

Any help would be appreciated.

Cheers,
xena

xena,

the OP is using a S8 VPAP Auto 25 bi-level machine. The respiratory rate data is something that I believe the S9 Elites and Autos don't track. It could be the Resmed auto-bi-level tracks this data because its part of the same series as the Resmed S8 VPAP S/T which is a bi-level machine with a timed back-up rate that (if I understand correctly) will up the pressure to the IPAP level if you don't start inhaling within a set period of time that's quite a bit shorter than the standard "10 seconds without breathing = an apnea". So it could be that respiratory rate data is needed for that.

Also all of S8's apparently don't have the detailed flow data. You can get an approximate respiratory rate for any time frame you want from the flow data: Just zoom into a one-minute interval and count the breaths for that minute. Of course, it might be nice to get an overall view of your respiratory rate rather than just an impression.

gvz---thanks for this info! I couldn't find it anywhere in my documentation. But maybe I didn't look quite hard enough.

robysue wrote:Your leaks are "ok" but not perfect.

Why the word "but"? The leak data is Great. As far as I'm concerned, it is perfect. Yes, it varies from zero once in a while, but is clearly way below the red line. Chasing a leak like that is a waste of time. allend, you need to spend your time on something likely to produce a benefit. It isn't fixing your leak "problem."

allend wrote:why the AIs when I sleep on my side?

Well, when are you sleeping on your side? I can't tell from what you wrote or from the graph. But in any event, the reason you are having apneas might be because the pressure is too high or too low at that point. I can't tell if you have any centrals. My guess is that the pressure needs to be higher than it is, because you are having a lot of obstructive apneas as well as a lot of hypopneas. HTH.

robysue wrote:gvz---thanks for this info! I couldn't find it anywhere in my documentation. But maybe I didn't look quite hard enough.

For those of you who don't know, gvz is the one who discovered this nice trick and let the rest of us in on it.

gvz wrote:

robysue wrote:The respiratory rate data is something that I believe the S9 Elites and Autos don't track.

The S9 Auto's and Elites do track respiratory rate. The machines store the data in one of the EDF files on the SD-Card. ResScan has an exclusion for it, for some reason. If you want to see it, just go into your ResScan.xml, get rid of all the <FG_DISABLE_LIST> tags, and Respiratory Rate will appear. Don't have to redownload data from the card. You can also unlock the Tidal Volume data also, but you'll need to adjust the scale of it in the detailed data pane to see it correctly.

There's also a bunch of exclusions in the ResScan.xml for the Escape's. I wonder if the Escape is actually writing all the same data as the Auto's and Elite's but simply turned off in ResScan.

Thanks for the info robysue and gvz - much appreciated - now I have a challenge for the evening LOL

gvz - ok, I found the .xml file and went to Edit, did a Find of the tag you mentioned, didn't find it, so I went through and looked and there's no <FG_DISABLE_LIST>

YIPPPEEEEEE!!! Nevermind... found it - looked again, but didn't find again with Find

WAIT!! What I found was </FG_DISABLE_LIST> AND <FG_DISABLE_LIST> - do I delete all of them?

Ok, deleted all tags as above, but now it won't let me save it, almost like it wants me to save it under a different name.

Thanks gvz - yes, I'm sorry and didn't intend to hijack this thread. I'll try what you suggest and post to a new thread if need be.

Cheers,
xena

LoQ wrote:

robysue wrote:Your leaks are "ok" but not perfect.

Why the word "but"? The leak data is Great. As far as I'm concerned, it is perfect. Yes, it varies from zero once in a while, but is clearly way below the red line. Chasing a leak like that is a waste of time. allend, you need to spend your time on something likely to produce a benefit. It isn't fixing your leak "problem."

allend wrote:why the AIs when I sleep on my side?

Well, when are you sleeping on your side? I can't tell from what you wrote or from the graph. But in any event, the reason you are having apneas might be because the pressure is too high or too low at that point. I can't tell if you have any centrals. My guess is that the pressure needs to be higher than it is, because you are having a lot of obstructive apneas as well as a lot of hypopneas. HTH.

I thought I said when I woke up at about 6:30, I switched to my side after coming back from the bathroom. I usually can't get back to sleep so this was unusual..but the results weren't so great for that period.

Does rescan report central apneas? I know Encore did. Is there a graph I'm missing that shows centrals?

allend wrote: Does rescan report central apneas? I know Encore did. Is there a graph I'm missing that shows centrals?

Yep, ResScan reports centrals---at least on the S9 series.

In ResScan, a central apnea is marked by a BLACK flag with a number on the top. The number is the length (in seconds) of the central apnea. So they look just like obstructive apneas except for the color.

ResScan also uses a YELLOW flag for apneas where the CPAP machine is unsure of whether an obstructive one or a central one.

gvz wrote: The S9 Auto's and Elites do track respiratory rate. The machines store the data in one of the EDF files on the SD-Card. ResScan has an exclusion for it, for some reason. If you want to see it, just go into your ResScan.xml, get rid of all the <FG_DISABLE_LIST> tags, and Respiratory Rate will appear. Don't have to redownload data from the card. You can also unlock the Tidal Volume data also, but you'll need to adjust the scale of it in the detailed data pane to see it correctly.

Thanks for these instructions. I'm happy about this. More data is always better!

There's also a bunch of exclusions in the ResScan.xml for the Escape's. I wonder if the Escape is actually writing all the same data as the Auto's and Elite's but simply turned off in ResScan.

This is a really interesting hypothesis. Maybe some poor soul who's been issued a brick could try this out and let us all know if the only real difference between the Escape and the Elite is a software issue with an easy work around.

allend wrote:Does rescan report central apneas? I know Encore did. Is there a graph I'm missing that shows centrals?

Yes, it does report central apneas, and no, you are not missing a graph. The problem is that the screenshot you showed has a bunch of apneas on top of each other, and I can't see if there are any central hidden below the top of that heap. All of the ones that are showing are obstructive.