Doing my own sleep study - surprising results

Colorado Jan wrote:Thanks for your words of encouragement Jerry...and I'm sorry, I wasn't trying to hijack your thread!

Just seemed logical to post my little results there since it was you that inspired me to try something. Yes, I do have an APAP and I'll probably be lowering the higher number next, since 9-15 probably too broad of a range. Seems that normally a spread of 4-5 is recommended, not 6.

I don't have the time nor patience (nor understanding, if we really want to get right down to it, lol) to do an in-depth study like you are doing.

Good luck with your continuing research! You are doing great! A true inspiration to us lazy ones!

Jan in Colo.

Jan, I welcome your participation. Just thought you'd get more attention with own topic. But, I also welcome any APAP experts to comment on your efforts in this thread.

Let's stick together.

Jerry

Jan in Colorado wrote:I currently have the Swift and like it quite a bit....but I'm on the Mask of the Month purchase plan, lol, and for this month's mask I've decided to buy a Breeze. So I can join in the discussion in a week or so.

I have the Swift, the Aura, the Activa and the Comfort Lite. I guess I'd have to say the Activa is my least favorite. The damn thing sucks onto my face so hard (talk about a good seal!..geez!) that it HURTS. And it leaves horrendous marks on my face. But no air is leaking out, that's for sure! As for the other three...I rotate them whenever one of them annoys me. Sometimes every few days...sometimes every few HOURS. Just seems to depend on my mood and how tolerant I am that day...

But after a night with the Activa recently, I got the idea of getting another interface that doesn't touch my face so much.....OUCH! Hence the new Breeze that will be coming soon....

Jan in Colo.

Jan, this is from an old post. Which interface do you like, now? Specifically, how did you like the Breeze. [I'd PM you with this question, but you don't have that option exercised in your 'Profile'.]

Jerry

viewtopic.php?t=6280

This looks like a good topic for you to consider in adjusting your APAP.

Jerry

<snip>
No autopap can do a perfect job all the time. But a straight cpap single pressure isn't necessarily perfect all the time, either. There are soooo many dynamics affecting breathing while we sleep. I believe the "love affair" many of us have for autopaps is justified in most cases. Not all. Just "most".

The point Wader makes is a good one... "considering an APAP can always become a CPAP, what do we have to lose?"

RG,

I would prefer an AUTO over CPAP for myself. I agree that there appears to be a high degree of satisfaction with AUTOs by those who have them and just from that point of view the "love affair" may well be justified.

I guess what I am wondering about is the significant discrepancy I was getting between what my RemStar AUTO was reporting & what my Spirit AUTO was reporting.

I ran tests by using each for two weeks & analysing the results daily. You may recall that in a PM to you I mentioned the incompatibility & IIRC you said you had observed similar.

The data appeared such that the two machines contradicted each other - one (Spirit) reported higher HI than AI by a factor of 4 while the other machine (Remstar), over a similar period reported AI with a factor of about 7 over HI. (Almost the reverse readings of AI vs HI).

After many discussions with my wife (who tends to track my sleeping patterns) I concluded the Spirit was probably more accurately recording what was happening & the Remstar data wasn't. It really bothered me that the two machines were so far apart in their interpretations & printed output reports. (I published the Spirit data on my website using the patient name John Doe - I haven't published the RemStar data but have stopped using it).

Assuming my observations were valid, then something is wrong with one AUTO compared to the other in terms of what they report. Again assuming my observations were correct, then a lot of folk with particular brands of AUTOs may be working off very flawed or greatly distorted data. Again, assuming my observations were correct, then I repeat that I wonder if the "love affair" with AUTOs may be misplaced.

Summary of concerns/questions:

Q1 Are all AUTOs able to report OSA events accurately ?
Q2 If there are discrepancies between brands of AUTO, how significant is this ?
Q3 If there are big discrepancies then what might this mean to those doing indepth evaluations ?

Cheers

DSM

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, auto, APAP

Jerry, thanks for steering me to that other thread. It was definitely worth reading!

As far as masks go, I think I am taking a rest from my search for the perfect mask. It just plain doesn't exist and you have to be in the right mood for a search for the Loch Ness Monster. I'll wait until the mood strikes me again to resume...

The Swift is my current favorite. Definitely the lesser of the evils, although last night the darn thing was definitely evil and wanted to slide off my head all night. I have shoulder length, fine, easily scrunched up hair and I think short hair or just a bald head would be definitely preferable in terms of mask comfort.

The Breeze has possibllities that I haven't thoroughly explored. I had it set up pretty well, I think....and I SWEAR my Spirit machine actually TOLD me that for the first portion of last night! Too weird! But like you said, it is definitely a nose grabber. Thought I had my nose taught to be pretty accepting of invading plastic thingies, but after a couple of hours of the Breeze it just couldn't take it anymore. I'll play with the adjustments again to see what I can do about that. It still has possibilities. OHHH, but I recall people saying it was good for side sleepers....that may be because you HAVE to sleep on your side since the headgear is totally uncomfortable when on your back! Can we say OUCH???

Re: the Aura. First I'm going to rubber band the thing according to that thread and if THAT doesn't work...then I'm going to hack the thing up according to RG's thread and take off that horrible headgear. That gives you a pretty good idea of how successful I've been with that mask.

The Comfort Lite really isn't all that bad. Have to tie it around the nose to keep it on but it isn't too bad.

The Activa can go back to the bottom of the sea where it belongs. Nuff said.

Sorry I don't have PM marked on my profile. Seems like I USED to get PM's. And I'd actually forgotten I even HAD a profile. I'll check into it.

DSM...

a low tech point of view....even if all the machines are not identical in their algorhythms (and I have to admit I don't even know what that IS)...must be something to do with their inner workings...wouldn't it still be in the best interest of the owner of that machine to tweak the numbers until it appeared to give the best result? Because wouldn't the best result, whatever that AHI number was, most probably still reflect some kind of improvement that would show on any of the machines? Sort of like when you weigh in at Weight Watchers, that weight isn't even remotely close to the scales at home...and the scales at home are totally different from the ones at the gym, but when it is all said and done, if all three scales go down, it still indicates that it was a good thing that you passed up the chips and salsa that week?

Oh, I should really shut up now before I show all you techies how REALLY stupid I can be, lol....

Jan in Colo.

Question : Are both APAPs operating correctly within manufacturers' specifications?

dsm wrote:

Assuming my observations were valid, then something is wrong with one AUTO compared to the other in terms of what they report. Again assuming my observations were correct, then a lot of folk with particular brands of AUTOs may be working off very flawed or greatly distorted data. Again, assuming my observations were correct, then I repeat that I wonder if the "love affair" with AUTOs may be misplaced.

Summary of concerns/questions:

Q1 Are all AUTOs able to report OSA events accurately ?
Q2 If there are discrepancies between brands of AUTO, how significant is this ?
Q3 If there are big discrepancies then what might this mean to those doing indepth evaluations ?

Cheers

DSM


CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, auto, APAP

DSM,

I continue to enjoy my Spirit Auto and I feel much better in the auto mode.
One reason for the different reading it the threshold levels that the machine is set for. Another possibility is that the RemStar has no way of knowing what the mask characteristic are and the Spirit has the mask selection setting to help with the therapy.
Bottom line did you compare the pressure curves to see if any pattern can be seen?

I appreciate the added comments but my post made this point

1 AUTO showed a pattern equiv yo 1 AI vs 4 HI (spirit)
the other for a similar period & under similar circumstances said
7 AI vs 1 HI (remstar) - a reverse opinion.

This is a *drastic* difference. If my observations are wrong then I am willing to look into them but I am by nature a generally cautious observer who double checks things rather than leap in & get caught short. I am of the opinion that a Remstar and a Spirit may well produce conflicting data in regard to AI vs HI.

I *totally agree* with any one who says the way one feels should be the real indicator, but many people here are placing great faith in what their AUTO machines are telling them when there are valid questions that say - is the data accurate & perhaps in some detail, is it even meaningful.

CPAP is dumb simple - x cms and the only dispute is going to be is it really x cms and a manometer will settle that.

With AUTOs I believe there is conflicting data being reported - in one sense it may not matter though as long as the person using that particular machine can get relative measurement from it even if the data they think they are getting is technically inaccurate.

Cheers

DSM

Jan:

Have you tried the TIP FOR SWIFT users on page one of the posts to help keep the SWIFT from sliding up in the back? It works well for me and you can use a different material if it grabs too much as ufo13 said by using the flat strip of velcro!

Tim

Colorado Jan wrote:The Swift is my current favorite. Definitely the lesser of the evils, although last night the darn thing was definitely evil and wanted to slide off my head all night. I have shoulder length, fine, easily scrunched up hair and I think short hair or just a bald head would be definitely preferable in terms of mask comfort.

Jan, I am bald but I'm pretty sure bald wouldn't look good on you.

Jerry

dsm wrote:I appreciate the added comments but my post made this point

1 AUTO showed a pattern equiv yo 1 AI vs 4 HI (spirit)
the other for a similar period & under similar circumstances said
7 AI vs 1 HI (remstar) - a reverse opinion.

This is a *drastic* difference.
With AUTOs I believe there is conflicting data being reported - in one sense it may not matter though as long as the person using that particular machine can get relative measurement from it even if the data they think they are getting is technically inaccurate.
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The seemingly different data reported by both machines is likely accurate in both cases. Both machines have fairly good sensitivity and specificity where apnea/hypopnea detection is concerned. Recall that you are reading "left over" apneas and hypopneas in both cases. And, also recall that both machines do not react merely in responsive mode. While both machines necessarily respond to obstructive events, both machines also leverage proactive treatment. The Remstar Auto, for instance, will intentionally attempt to induce an inconsequential flow limitation toward measuring airflow deltas, and then, in turn, extrapolating the next target pressure.

When you read drastically different AI and HI numbers from two different AutoPAPs, you are less likely reading an AI/HI measurement error in any one machine. Rather, you are more likely reading that one machine's algorithm happens to be treating you better. After all, in both cases you are reading "left over" apneas/hypopneas after the machine's responsive algothithmic techniques coupled with that same machine's proactive techniques takes it's best shot at treating your particular breathing patterns.

Different AI and HI does not necessarily mean either machine is measuring either obstructive sleep event incorrectly.

One other question deals with either manufacturer's definition or cut-off point between scoring an obstructive sleep event as a hypopnea versus scoring that same obstructive sleep event as an apnea. While the Remstar Auto uses the more sensitive flow sensor of those two machines, either sensor type is more than capable of measuring flow limitation well enough to distinguish apnea versus hypopnea. However, the apnea/hypopnea definitions or cut-off point may actually be different between these two models by design.

AutoPAP manufacturers do not necessarily agree on how to score sleep events, and there are subtle differences in scoring criteria. Anyone whose sleep events tend to consistently border between hypopnea and apnea may return drastically different AI-to-HI ratios between two different manufacturers for this reason.

Back to topic, which, admittedly, is becoming trite.

I went to 9 cm from 10 cm last night and expected AHI's around 1.0 from the curve that had been generated by My Encore for the previous data. Surprise, the AHI dipped to 0.22. Snore Index went up a little but not significantly.

Here is a plot of the pressures I have used:



Here are the Daily AHI results:



Here is the Pressure vs. AHI plot, which shows the dip for 9 cm last night:



And, finally the ME daily report. Note, there are only 2 hypopneas and no apneas.



I used the Aura mask with the rubber band to get a better seal. Worked great!

Oh, yeah, and Daily Snore Index:



I'm going to keep the 9 cm setting for a few nights, at least. I'll wait to post charts until I see if the average AHI changes much.

Jerry

AutoPAP manufacturers do not necessarily agree on how to score sleep events, and there are subtle differences in scoring criteria. Anyone whose sleep events tend to consistently border between hypopnea and apnea may return drastically different AI-to-HI ratios between two different manufacturers for this reason.

Thank you, Guest, for explaining why discrepancies in data reports from different manufacturers' machines are to be expected and are not an indication that there's something wrong with one or the other.

rested gal wrote:

AutoPAP manufacturers do not necessarily agree on how to score sleep events, and there are subtle differences in scoring criteria. Anyone whose sleep events tend to consistently border between hypopnea and apnea may return drastically different AI-to-HI ratios between two different manufacturers for this reason.

Thank you, Guest, for explaining why discrepancies in data reports from different manufacturers' machines are to be expected and are not an indication that there's something wrong with one or the other.

RG,

Speaking for myself,
I was quite concerned as if my events were predominantly Hypopneas, then it tended to back up my wife's observations that I was slowing then stopping breathing and that this seemed to be happening again about 2.5 months after I started CPAP. The first 2.5 months seemed like all my prayers answered then my wife began noticing that even when on 14.5 cms and on CPAP *or* AUTO, I was slowing & stopping breathing again. The Spirit seemed to report this accurately. I also was starting to feel tired & lose my energy levels.

If I had been relying on the RemStar stats that showed few hypopneas but predominantly apneas, then I may not have tried a BiLevel that actually thus far has shown a big improvement to my energy levels. I am using A/C mode to make certain that if my breathing rate drops below 6 BPM the machine switches to IPAP which is set to 15cms & seems to get me breathing again.

The condition I seem to be working thru is more related to slowing breathing than to having obstructions. My desire is to maintain energy levels and well being during the day. I really want accurate feedback on what my machine detects. I don't want guesswork.

I am not clear how it can be good that there is such a discrepancy between reports from 2 main brands of AUTO. Saying it is simply a difference in how 2 different manufacturers interpret results seems a very weak argument. It certainly bothered me enough that I lost confidence in my RemStar AUTO reporting. Otherwise, I regarded it as my most robust & quiet machine. I now intend selling it.

Cheers

DSM