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[Equipment] How Accurate is the Data???
#1
How Accurate is the Data???
Hello All
First the General Info
I have severe sleep apnea, both central and obstructive. with sleep studies showing between 120 and 175 events per hour depending on the study
I have been using VPAP and CPAP machines for more than 10 years
I have had this ResMed machine for just under a year

Current Setup
Mode ST
Ipap - 23.4
Epap - 18.4
Resp rate 11
Ti Max 4
Ti Min 2.2

I use Sleepyhead to read the data from the SD card and display it.
My charts show that I have not had a peak AHI of over 12 in the last 2 months. Normally the peak is between 4 and 8.
The mask pressure chart shows the machine maintaining it's pressure set points
Leaks are minimal
That all sounds really great.
But 5 or 6 times in the last two months, I just have terrible nights, where I can remember waking up, falling asleep, again and again, waking up in the morning a complete zombie.
The only times I have had this happen before was when I was having problems with a machine.
Yet the charts are showing no issues.

So my question is, how accurate is the data? The techs all swear it's absolutely perfect, but my body is saying something very different.
As an electrical designer and programmer, I am also well aware that what gets recorded is not always the entire story.
It's really hard to argue with the techs when they point to the charts and say "It's just fine. You don't have a problem" and you are so zonked out you can hardly think.

Any insights would be appreciated
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#2
RE: How Accurate is the Data???
It's fairly accurate from a machine stand point. Each generation of machines just keeps getting better and better at not just treatment, but determining what treatment is needed.

Also, there's a lot of factors that go into a good or bad night's sleep. If it were happening every other night, then there'd be reason for concern about accuracy.

That said, consider also installing and using ResScan to compare. You won't see detailed data for anything over 7 days but it can help for future nights.
PaulaO

Take a deep breath and count to zen.




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#3
RE: How Accurate is the Data???
(09-18-2013, 09:37 PM)johntrottier Wrote: Hello All
First the General Info
I have severe sleep apnea, both central and obstructive. with sleep studies showing between 120 and 175 events per hour depending on the study
I have been using VPAP and CPAP machines for more than 10 years
I have had this ResMed machine for just under a year

Current Setup
Mode ST
Ipap - 23.4
Epap - 18.4
Resp rate 11
Ti Max 4
Ti Min 2.2

I use Sleepyhead to read the data from the SD card and display it.
My charts show that I have not had a peak AHI of over 12 in the last 2 months. Normally the peak is between 4 and 8.
The mask pressure chart shows the machine maintaining it's pressure set points
Leaks are minimal
That all sounds really great.
But 5 or 6 times in the last two months, I just have terrible nights, where I can remember waking up, falling asleep, again and again, waking up in the morning a complete zombie.
The only times I have had this happen before was when I was having problems with a machine.
Yet the charts are showing no issues.

So my question is, how accurate is the data? The techs all swear it's absolutely perfect, but my body is saying something very different.
As an electrical designer and programmer, I am also well aware that what gets recorded is not always the entire story.
It's really hard to argue with the techs when they point to the charts and say "It's just fine. You don't have a problem" and you are so zonked out you can hardly think.

Any insights would be appreciated

can you put the data in ResScan and see if there is a difference in the results? Just a thought.
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#4
RE: How Accurate is the Data???
Hi johntrottier,
WELCOME! to the forum.!
Hang in there for more responses to your post.
trish6hundred
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#5
RE: How Accurate is the Data???
In my opinion, AHI and event measurement is not really that well "defined."

One set of breathing patterns may count as an apnea, while something just a little bit less doesn't get flagged.

In a lot of ways, it doesn't matter that much because the machine will correctly flag severe events. You can detect the significant events for most of the patients.

However, if you're "borderline" for much of the night, that's much less well understood. Sometimes, they use terms like RERA, UARS, hypoventilation, etc. Diagnosis and treatment of these conditions is much less clear even with the right conditions. CPAP machines are not as "smart" about these conditions as they are about "regular" OSA and CSA.

Also, CPAP machines can't see EEG and chest effort that is used in sleep labs.

I think to some extent, the answers are often there in the waveforms. (Airflow, minute vent, etc.) Unfortunately, the interpretation is a LOT tougher.

There's also a problem that even if the "mechanical" aspects are taken care of, your brain may respond to breathing events more quickly than the machine and partially or completely wake you up. i.e. your airway closes up, but your brain panics before the machine recognizes anything and wakes you up and stops the apnea.

Sometimes, some experimental adjustments based on feelings, not CPAP data help. For instance, I feel better if I increase my minimum pressure above the level that eliminates most of my AHI. I think it eliminates some "ragged" breathing, RERA, and related stress.
Get the free OSCAR CPAP software here.
Useful links.
Click here for information on the main alternative to CPAP.
If it's midnight and a DME tells you it's dark outside, go and check it yourself.
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#6
RE: How Accurate is the Data???
I use Sleepyhead to read the data from the SD card and display it.
My charts show that I have not had a peak AHI of over 12 in the last 2 months. Normally the peak is between 4 and 8.
The mask pressure chart shows the machine maintaining it's pressure set points
Leaks are minimal

If I understand your post correctly at 2:51 AM, AHI of 12 per hour is high and may be why you don't feel rested and like you are getting quality sleep those 5 or 6 nights.

Just a thought. Dont-know
Post Reply Post Reply
#7
RE: How Accurate is the Data???
(09-19-2013, 01:19 AM)archangle Wrote: In my opinion, AHI and event measurement is not really that well "defined."

One set of breathing patterns may count as an apnea, while something just a little bit less doesn't get flagged.

In a lot of ways, it doesn't matter that much because the machine will correctly flag severe events. You can detect the significant events for most of the patients.

However, if you're "borderline" for much of the night, that's much less well understood. Sometimes, they use terms like RERA, UARS, hypoventilation, etc. Diagnosis and treatment of these conditions is much less clear even with the right conditions. CPAP machines are not as "smart" about these conditions as they are about "regular" OSA and CSA.

Also, CPAP machines can't see EEG and chest effort that is used in sleep labs.

I think to some extent, the answers are often there in the waveforms. (Airflow, minute vent, etc.) Unfortunately, the interpretation is a LOT tougher.

There's also a problem that even if the "mechanical" aspects are taken care of, your brain may respond to breathing events more quickly than the machine and partially or completely wake you up. i.e. your airway closes up, but your brain panics before the machine recognizes anything and wakes you up and stops the apnea.

Sometimes, some experimental adjustments based on feelings, not CPAP data help. For instance, I feel better if I increase my minimum pressure above the level that eliminates most of my AHI. I think it eliminates some "ragged" breathing, RERA, and related stress.

Thank you for you great post.
I suspect you hit the nail on the head with the statement that not all events are flagged
I keep working on it

Thanks to all for the advice

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