It knows when you are sleeping, but will it tell you?

[MJS_]

Thanks for your detailed response Pugsy! I've not yet taken the time to learn/explore the OSCAR program, but I have used it to view the summary statistics which F&P hides from patients. I did figure, though, that it would be necessary to turn the machine off and on to create a discrete data set.

I wake up a few times each night to urinate due to BPH, so I suppose I'll also be getting false positive flags?

Once I adjust to the CPAP and dial in the pressure/comfort settings based on the machine's AHI stats and how I feel, I was planning to send my data to a consultation service like the one operated by TheLankyLefty to find out whether or not the AHI stats are a valid indicator of my therapy's efficacy. One of Mr. Lefty's videos already helped me with my settings by teaching me that the headache I woke up with after using CPAP could have been caused by my machine's Expiratory Relief feature (which can trigger episodes of hypopnea); I switched it off and no more headaches (so far).

[Pugsy]

One of Mr. Lefty's videos already helped me with my settings by teaching me that the headache I woke up with after using CPAP could have been caused by my machine's Expiratory Relief feature (which can trigger episodes of hypopnea); I switched it off and no more headaches (so far).

Turning off EPR effectively raises the treatment pressure a little (how much depends on what setting is being used for EPR) so the positive results you attribute to turning EPR off just means that you likely needed a little more baseline pressure to better prevent the airway collapses from ever happening.

I am not so sure that EPR caused your headaches....I use what would be the equivalent of EPR at 4 cm with my bilevel machine and I don't get any headaches now. I used to pre-cpap have lots of morning headaches that were really bad.
The headaches come from low oxygen levels caused by the apnea episodes. During my in lab diagnostic sleep study my O2 tanked at 73%. EPR doesn't normally cause low O2 which causes the apnea related headaches (as opposed to headaches from non apnea related medical issues) but sub optimal therapy from pressures being too low sure can.

Jason (TheLankyLefty) has some ideas about a few things that I don't agree with and I am not alone.
He doesn't like auto adjusting mode and he doesn't like EPR but IMHO his reasoning just doesn't hold up.
He seems to tend to believe that if something causes a problem for a few people that no one should ever use it. I don't feel that way.

I love Jason to death and pick his brain often but I don't agree with some of his thinking. That's okay....he doesn't always agree with my thinking either.

[Dog Slobber]

It's common knowledge that sleep/awake cannot be accurately determined without EEG.

If this were common knowledge, ResMed and F&P would not advertise that their machines can be set to ramp up the air pressure after detecting you have fallen asleep. For example: https://www.youtube.com/watch?v=BrGGgYolGfI

They most certainly can.

Advertising and promotional material do not have to be absolutely, technically accurate.

A lot of leniency is extended to this this kind of material that allows general statements to be expressed, even though there are exceptions. I've found ResMed's algorithm to be very good at determining when *I've* fallen asleep. But there are exceptions.

Lookup "Puffery", it's the standard legal defense that allows advertising and promotional material to exaggerate claims and sometimes even state claims that are simply not true, and get away with it.

[ChicagoGranny]

If you find their promotional materials say the machine uses EEG, sue them.

[ChicagoGranny]

If you find their promotional materials say the machine uses EEG, sue them.

But you have to state what the damages were. Mere emotional irritation won't get you much.

[Pugsy]

If you find their promotional materials say the machine uses EEG, sue them.

But you have to state what the damages were. Mere emotional irritation won't get you much.

Well....one could join one of those torte lawsuits and at least the lawyers will get a new house out of the deal.
The actual patients will be lucky to get enough money to buy a grande latte at Starbucks.

[palerider]

It's common knowledge that sleep/awake cannot be accurately determined without EEG.

If this were common knowledge, ResMed and F&P would not advertise that their machines can be set to ramp up the air pressure after detecting you have fallen asleep. For example: https://www.youtube.com/watch?v=BrGGgYolGfI

Wow, you're really wound up about nothing.

If you squint carefully, you'll probably find some * in the Auto Ramp*

*doing our best guess to try and help you, but not perfect.

[Dog Slobber]

If you find their promotional materials say the machine uses EEG, sue them.

But you have to state what the damages were. Mere emotional irritation won't get you much.

Well....one could join one of those torte lawsuits and at least the lawyers will get a new house out of the deal.
The actual patients will be lucky to get enough money to buy a grande latte at Starbucks.

This *ACTUALLY* happened, in Canada.

Canada has a somewhat iconic coffee and donut shop chain, Tim Hortons. Though it's no longer Canadian owned.

A few years ago, it was learned that their app was inappropriately and covertly tracking those who had installed it. A class action suit was launched.

Tim Hortons proposed a settlement of a free coffee and donut to everyone who had the app during the time the alleged tracking was taking place. Their offer was accepted.

https://www.narcity.com/tim-hortons-cla ... aked-goods.

[MJS_]

It's common knowledge that sleep/awake cannot be accurately determined without EEG.

If this were common knowledge, ResMed and F&P would not advertise that their machines can be set to ramp up the air pressure after detecting you have fallen asleep. For example: https://www.youtube.com/watch?v=BrGGgYolGfI

Wow, you're really wound up about nothing.

....

I was not wound up, and I did not expect my little assertion to be controversial! I was not making a legal liability argument. Rather, I was implying that ResMed and F&P would be foolish to advertise a claim that most of their potential customers believed to be false.

I just picked up my new ResMed CPAP machine from my DME provider and their certified respiratory therapist did an orientation to the machine for me. When he got around to explaining the Auto-Ramp feature, I said "This thing can't really tell when you are asleep or awake, can it?" He assured me that it does a good job detecting whether your asleep or awake based on breathing patterns. So I maintain my position that it is NOT common knowledge that these machines are unable to do this (but I'm not wound up about it ).

[MJS_]

One of Mr. Lefty's videos already helped me with my settings by teaching me that the headache I woke up with after using CPAP could have been caused by my machine's Expiratory Relief feature (which can trigger episodes of hypopnea); I switched it off and no more headaches (so far).

Turning off EPR effectively raises the treatment pressure a little (how much depends on what setting is being used for EPR) so the positive results you attribute to turning EPR off just means that you likely needed a little more baseline pressure to better prevent the airway collapses from ever happening.

...

Jason (TheLankyLefty) has some ideas about a few things that I don't agree with and I am not alone.
He doesn't like auto adjusting mode and he doesn't like EPR but IMHO his reasoning just doesn't hold up.
He seems to tend to believe that if something causes a problem for a few people that no one should ever use it. I don't feel that way.

I may be one of the few people for whom EPR can trigger episodes of hypopnea. My AHI for the session that caused a headache was around 2. Since turning off EPR, I have inched my min/max pressure settings a bit lower without causing headaches or higher AHI numbers. Now that I have a somewhat better understanding of obstructive versus central apnea events, I'll play closer attention to my session data if/when I decide to give EPR another try.

[ChicagoGranny]

I was not wound up, and I did not expect my little assertion to be controversial!

Mouth tape, distilled water, washing hoses in the sink - everything is controversial here.

[chunkyfrog]

Or not.

[robysue1]

It's common knowledge that sleep/awake cannot be accurately determined without EEG.

If this were common knowledge, ResMed and F&P would not advertise that their machines can be set to ramp up the air pressure after detecting you have fallen asleep. For example: https://www.youtube.com/watch?v=BrGGgYolGfI

Both Resmed and F&P are using the fact that normal sleep breathing has certain characteristics that are quite different from normal wake breathing to make a decent, educated guess as to whether there is a high probability that the person using the machine is asleep. With both machines, the idea is not to try to pinpoint the exact moment you fall asleep (or wake up with SensAwake); rather the idea is to increase patient comfort by limiting pressure increases to times when the patient has a high probability of being asleep. (The idea is that once we're asleep, pressure increases should not bother us enough to wake us up. Whether that's a valid hypothesis is a whole different question.)

Information about Resmed's AutoRamp was pulled from https://www.resmed.com/en-us/sleep-apne ... -pressure/

In the case of Resmed's AutoRamp, the machine is looking for one of the following three things before it starts to ramp the pressure up:

• 30 breaths of stable breathing (roughly 3 minutes)
• 5 consecutive snore breaths
• 3 obstructive apneas or hypopneas within 2 minutes
• 30 minutes have passed since the machine was turned on

It's clear that in choosing those criteria for ending the AutoRamp, Resmed is making the following assumptions:

• Three minutes (i.e. 30 breaths) of stable breathing looks more like good, normal breathing than "wake" breathing. So you are likely asleep (and hence not likely to be disturbed by the pressure increasing.)
• Snoring occurs when the patient is asleep. Now it's important to remember the Resmed PAPs don't have a sound detector built in---snoring is characterized by particular distortions in the flow rate graph. By using 5 consecutive snores, they hope to avoid instances where a person may make a snoring kind of breath once or twice in the process of falling asleep.
• Three OAs or Hs occurring within a short period of time (2 minutes) indicates that if the person is asleep, their airway is unstable and in need of additional pressure. Hence the need to start ramping up the pressure. By using multiple events in a short period of time, Resmed is hoping to avoid ramping up the pressure in response to the occasional false positive OA or H scored during wake breathing that are perfectly normal for the patient's wake breathing patterns. (It's important to realize that some people do see OAs scored when they consciously hold their breath while awake and using the machine.)
• Most people have a latency to sleep of 10-20 minutes at the beginning of the night. So even if 30 breaths of stable breathing has not yet been detected, there's a good chance the patient is asleep and the continued raggedness of the breathing may, in fact, be due to sleep disordered breathing which warrants a pressure increase if that raggedness could be described as "flow limited breathing".

The goal here is to use the machine's one source of data---the flow rate curve---to detect when the patient is most likely asleep instead of still awake at the beginning of the night. And the hope is that if the machine keeps the pressure at a constant low pressure while the person is awake, that person will have an easier time falling asleep. Whether that assumption itself is correct is a valid question: Many people here will tell you that they feel like they're suffocating at pressures in the 4-6cm range and they are quick to tell newbies to ditch the ramp and start at a higher pressure when a newbie complains they feel like they're suffocating.

Now I don't know enough about F&P's SensAwake algorithm, and what I could find on line was pretty pitiful. But based on what Rubicon posted, it looks like F&P is looking for restless wakeful breathing (including what is often called Sleep-Wake-Junk around here). And the F&P machines are supposed to lower the pressure (how much?) in an effort to make it easier to get back to sleep. Does that work for real people in real beds? I suspect the answer is sometimes. If you are someone who has dealt with a lot of aerophagia and is uncomfortable (and worried about aerophagia) anytime you wake up in the middle of the night, knowing the machine is supposed to reduce the pressure a bit may help alleviate the worrying which in turn will help with getting back to sleep. But if pressure doesn't really bother you OR if you dislike low pressure, that pressure reduction probably isn't going to help very much with getting you back to sleep.

In other words, I think both Resmed's AutoRamp and F&P's SensAwake probably do make reasonable guesses most of the time when they think the person at the other end of mask is likely asleep at the beginning of the night. But neither algorithm is designed to try to measure exactly when the transition between sleep & wake precisely took place at the beginning of the night. And it's not at all clear to me whether the F&P SensAwake algorithm is really going to pick up SWJ breathing well enough to decide to lower the pressure and whether lowering the pressure is even the best thing to do in terms of helping the person get back to sleep.

[robysue1]

Well, Sensawake might work. It looks for Fig. 7:



IIWM, I'd call that Wake.

Where did you get that figure from Rubicon?

Cause I haven't been able to find anything about what SensAwake is using to determine wake vs. sleep.

[Dog Slobber]

When he got around to explaining the Auto-Ramp feature, I said "This thing can't really tell when you are asleep or awake, can it?" He assured me that it does a good job detecting whether your asleep or awake based on breathing patterns.

Sounds like you're not aware that the following two statements:

• Sleep/awake cannot be accurately determined without EEG, and
• ResMed's Auto-Ramp feature can do a good job detecting whether you're asleep or awake based on breathing pattern

Can both be true.