Runaway pressure increase with resmed auto S8

Slinky · Post by **Slinky** » Fri Jul 20, 2007 6:47 pm

Now there you go, SnoreDog. Confusing me! What is the difference between Ramp and Settling?

Is the Ramp only available during CPAP mode and Settling only available during Auto mode?

Just as I think I've got it figgered out somebody's gotta confuse me again.

Ramp starts low and gradually builds up pressure during the set period?

Settling just doesn't bother to score or respond to any events during the set period?

ozij · Post by **ozij** » Sat Jul 21, 2007 12:29 am

Exactly.

Ramp starts low and gradually builds up pressure during the set period.

Settling just doesn't bother to score or respond to any events during the set period.

(Question marks deleted... )
O.

dsm · Post by **dsm** » Sat Jul 21, 2007 2:17 am

[quote="GoofyUT"]Hold on there, Barb. What you're describing is perfectly normal for the ResMed S8 Vantage and many of us here, as well as several sleep labs, have observed and documented the very same phenomenon. It has to do with the "settling time" parameter on the Vantage. If "settling" is NOT enabled, the Vantage begins scoring flow degradations as soon as it starts up and begins titrating to treat them. This includes what you would consider to be your "normal" wakeful breathing, which is NOT the same as the autonomic breathing that you do while asleep. The Vantage gets confused by your wakeful breathing and tries to treat it by increasing pressure, while it really is designed to score and treat only autonomic breathing while you are asleep. It is for this reason that they include the "settling" function. That SHOULD be enabled and set to the period that it normally takes you to settle in and fall asleep. By doing so, you're disabling the scoring algorithm during that time, and the machine will simply plug along at its lowest auto pressure until you've usually fallen asleep. It'll then begin scoring flow degradations of your autonomic sleep breathing, and treat them VERY effectively.

I struggled with the very same thing until I figured out the "settling" function, set it to 20 minutes or so, and VOILA, the increases in pressure while I was awake ceased immediately! And, my AHI dropped sharply too, since it was not scoring hypopneas artifactually while I was awake. So ENABLE SETTLING and your problem will be solved.

Unfortunately, I didn't respond well to the flow dynamics of the ResMed algorithm, so I switched to a REMstar Auto, which I respond much better to. But, it sounds like you do respond well to ResMed's algorithm, and I think that it is a GREAT machine for those who respond to it well; The very BEST in terms of human factors design, form factor, size and travel-friendliness.

So, RELAX, enable settling and you'll be fine!

Hope this helps.

Chuck

dsm · Post by **dsm** » Sat Jul 21, 2007 2:21 am

[quote="Slinky"]Now there you go, SnoreDog. Confusing me! What is the difference between Ramp and Settling?

Is the Ramp only available during CPAP mode and Settling only available during Auto mode?

Just as I think I've got it figgered out somebody's gotta confuse me again.

Ramp starts low and gradually builds up pressure during the set period?

Settling just doesn't bother to score or respond to any events during the set period?

Slinky · Post by **Slinky** » Sat Jul 21, 2007 5:59 am

Ha! The hypopneas are my downfall. So, if I use the Vantage in CPAP mode even, the Settling will still work?

Darn! I've gotta keep the compliance going on the Elite for 3-5 more months for insurance purposes or risk losing it. *sigh*

GoofyUT · Post by **GoofyUT** » Sun Jul 22, 2007 1:02 am

[quote="Snoredog"][quote="barbpsleep"]GoofyUT, I wonder what helped determine that your airflow fit the remstar better than resmed? Who was able to differentiate between the algorithms?

And, also, is that a German Shorthaired Pointer in your photo? It's a beautiful dog.

Thanks again,

Barbara

Snoredog · Post by **Snoredog** » Sun Jul 22, 2007 1:35 am

[quote="GoofyUT"][quote="Snoredog"][quote="barbpsleep"]GoofyUT, I wonder what helped determine that your airflow fit the remstar better than resmed? Who was able to differentiate between the algorithms?

And, also, is that a German Shorthaired Pointer in your photo? It's a beautiful dog.

Thanks again,

Barbara

dsm · Post by **dsm** » Sun Jul 22, 2007 3:12 am

[quote="GoofyUT"][quote="Snoredog"][quote="barbpsleep"]GoofyUT, I wonder what helped determine that your airflow fit the remstar better than resmed? Who was able to differentiate between the algorithms?

And, also, is that a German Shorthaired Pointer in your photo? It's a beautiful dog.

Thanks again,

Barbara

dsm · Post by **dsm** » Sun Jul 22, 2007 5:25 pm

This post follows on Chuck's comments re why the Remstar Classic machine suited him better than a Resmed S8 machine. Chuck, please feel free to comment on or to correct any of my comments below. What I am posting below is just my own impressions & observations.

When Chuck 1st made this comment re the difference between Remstar & S8 Vantage (IIRC back in 2006) I wondered what he could be meaning. In one sense a cpap machine is an air pump & how could a simple air pump be so different for one person vs another. I thought masks yes, but how could the cpap unit itself vary so much that one brand is going to pump air better than another ?.

The main challenge I had was trying to figure out in mechanical/technical terms what Chuck was saying about the Resmed being 'aggressive' & the Remstar being 'softer'. I asked myself at the time "how can air flow be 'aggressive' or 'soft'". What was he really saying.

I had started out my cpap life on a Remstar classic tank & have in many many posts sung its praises as one of Respironics great products. I also have tried the Resmed S6, the S7 Elite (cpap) the S7 Spirit (auto) S8 Escape (cpap) and S8 Vantage (Auto) as well as several Vpap III Bilevels. The Vpap IIIs have exactly the same blower assembly as the S7 models whereas the S8 has a newly designed blower.

The more I tried different machines, the more I believe I began to understand what Chuck was conveying re aggressive vs soft.

Apart from the Auto algorithms that drive the pressure raising aspect of the Auto, there are other elments that can and do make a difference to the comfort for one cpap user versus another. When it comes to debating algorithms, the debates can get quite 'religious' and I am not into going down that theme in this thread (not without my best armour on )

What can and does make a noticable difference between one brand and even models within brands are things like how fast the machine's blower can accelerate & how quickly the motor can be slowed combined with how quickly the sensors can report the changes (pressure & airflow) & respond to them. What seemed to come through to me is that with the Resmed models the blower could accelerate fast but the pressure sensing circuits in the machine seemed to lag the motor enough that the pressure would 'overshoot' and in time this effect struck me as what Chuck was describing as 'aggressive'.

The Remstar classic has a biggish motor in it. The newer M series motor is tiny by comparison. The Remstar classic seemed to be a better tuned unit when it came to motor performance and sensor synchronisation. This gave what I believe Chuck calls the softer feel of the Remstar classic.

On the algorith side of the debate, the speed with which the various machines, *increase CMS* when events are detected is so slow over all that I can't really see that being a problem to anyone. If anyone does find that a problem they shouldn't be on an Auto as future Autos may do it even faster. The C-Flex debate makes far more sense in that C-Flex offers great comfort to some people but causes some problems for others (aerophagia, breath stacking etc:). C-Flex has everything to do with how an individual person reacts to breath by breath changes occuring when transitioning from inhale to exhale.

The Resmed machines do seem to raise pressure a bit quicker in response to obstructions and snore vibrations. Am satisfied from conducting various tests re this. But that is a minor issue compared to how well a particular machine transitions from inhale to exhale. I am convinced that this is the point where people vary greatest & thus react most to a particular model of machine.

One issue I had with the Resmed S7 blowers (& thus Vpap IIIs as well) is the whine they make as they change speed in response to breathing in and out. Interestingly, Respironics now have this problem with their M series machines. The Bipaps & Classic models don't behave that way.

So in summary, am saying that there are many factors that can make one brand of machine seem better than another and then this can vary between models within brands. I am now of the opinion that getting the 'perfect' cpap machine has little to do with 'brands' but a lot to do with individual designs & combinations & that finding whats best for oneself is still a hit and miss exercise.

Hppy searching (for that perfect machine )

DSM

ozij · Post by **ozij** » Sun Jul 22, 2007 11:26 pm

Very interesting points, DSM.
Thanks,
O.

dsm · Post by **dsm** » Mon Jul 23, 2007 2:57 am

ozij wrote:Very interesting points, DSM.
Thanks,
O.

Thanks Ozij, it is such an interesting issue.

Have been able to demo to myself that increasing resistance to the ipap to epap 'switch' by changing the risetime settings, does vary the effect of aerophagia for myself (allowing that I am impacted by GERD & obviously have a weakened valve between stomach & esophagus & thus this ipap/epap switch becomes important).

The S8 with EPR provides greater resistance to the ipap to epap switch than does my PB330 Knightstar & the elevation in aerophagia is almost predictable. The S8 offers no adjustments which it really needs.

Now I want to find a way to earbash the Resmed designers to soften the switch for us older folks with GERD who can't stop the few little bubbles of air that escape into the stomach when going through that initial breathe out part of the cycle. C-Flex at 3 did the same to me.

D

sleepyred · Post by **sleepyred** » Mon Jul 23, 2007 6:07 am

Please excuse my lack of knowledge here, but what does

CMS

stand for?

ozij · Post by **ozij** » Mon Jul 23, 2007 6:35 am

I stumbled on that one also for a minute. CentiMeterS (of water pressure)...
O.

sleepyred · Post by **sleepyred** » Mon Jul 23, 2007 6:36 am

Thanks!!!!!!!!!!!!!!!!!!!!!

ozij wrote:
I stumbled on that one also for a minute. CentiMeterS (of water pressure)...
O.

barbpsleep · Post by **barbpsleep** » Mon Jul 23, 2007 8:29 pm

I didn't anticipate that my question would generate so much discussion and provide so much information. I realize that there are still some differences of opinion, but thank you all for replying. My DME left a message asking what I'd learned from the forum. It's amazing to me that these professionals don't monitor the forums to broaden their knowledge from the large number of very proactive patients here.

I'm going to share with the DME that others have reported the same phenomenon that I've experienced. There seems to be a general consensus that the settling feature should be enabled to disable the algorithm that doesn't properly address the greater variations in wakeful breathing. It seemed to help me. I wasn't aware of anything particularly unusual about my wakeful breathing, but whether it's the deviated septum or some greater narrowing or a vibration, something is causing the machine to sense problems where there aren't any.

I'll also share the belief expressed by several of you with obviously great experience in comparing machines that the REsmed may indeed raise pressure faster in response to obstructions and vibrations, or the faster blower may lead it to be more aggressive in pressure increases, and/or it's slower in sensing that it needs to drop the pressure back down. Not clear from what everyone's said whether it's the algorithm or the engineering, but in any case, it's not really so very unusual.

I am still frustrated and tired with continued waking, though it may now be only a couple of times that I'm aware of. I do think I'm sleeping deeper with the Resmed. No apneas at all last night and an HI under 4 the two nights I checked. But I long to sleep through the night. I don't know if I'm just a light sleeper and I'm waking during the hypopneas, or if I'm waking because of the pressure rising quickly, which I see when I wake, or sense because of the need for exhale relief.

I think I'll try the plus/minus 2 rule and drop my upper pressure a bit more. I haven't connected the humidifier yet. Didn't take it with when I first got the machine for a test while traveling and I really don't like the warm air feel in the summer. But perhaps I should because last night, I woke with a very dry mouth - so dry that I was dreaming that it was hard to talk.

I will continue with the REsmed for another week or so, but I'll ask to test the Respironics with A-flex, at least in the office so I can hear it. I'm concerned about the noise and lights, and it seems strange that there should be so much variation in the individual machines people have received. I know there are individual tolerances, but given the very widely disparate experiences, it seems more than this. I also really like being able to see results in the morning on the Resmed. It sounds like this is more difficult with the Remstar and possibly more difficult now because of software problems. Still not sure what's best.

Well, thanks again everyone. I do appreciate all of the information and the validation that my experience isn't something totally unheard of.

Barbara

Runaway pressure increase with resmed auto S8

Re: Settling

Re: algorithms and switch resmed to remstar - how'd you know

Re: algorithms and switch resmed to remstar - how'd you know

Re: algorithms and switch resmed to remstar - how'd you know

Mask

Additional Comments: Aussie Heated hose for rain out/PapCap Headgear and chin strap