Sleepyhead Data Weirdness

[courtney123]

Last night in a fit of boredom, I was rummaging through the setup menu on my CPAP machine looking at results.
"Last 7 days - AHI: 0."
Huh?
No apneas?
Not according to Sleepyhead which says I average between 1 and 3 a night.

For the Sleephead experts: Does Sleepyhead interpret the data or just take what the machine gives it?

For another example - from last night (N1.jpg) it sees this as an hypopnea.
Not close.

What do you trust? Sleephead or the machine?

[Paptillian]

SleepyHead generally reports higher numbers than the other software I use (ResScan) but it's not a huge difference. I don't know which is more accurate.

I think I had read that hypopneas are scored as a 40% reduction in flow for 10 seconds followed by a recovery breath. There doesn't need to be a flat line in the flow.

[courtney123]

I think I had read that hypopneas are scored as a 40% reduction in flow for 10 seconds followed by a recovery breath. There doesn't need to be a flat line in the flow.

Yeah, read that too. The readout has no difference in the flow for several minutes on either side of that marker.
That's one of the thing's that are making me question the accuracy.

Thanks.

[PaulaO2]

It is also possible that the machine is not displaying it properly.

SleepyHead and ResScan are both fairly close for my data. It seems as though they round off the numbers differently.

That is a hypopnea in the image. It is flatter than those around it. Granted, not by much but enough to register. When it comes to hypopneas, I look at length, not that one was counted.

[courtney123]

It is also possible that the machine is not displaying it properly.

SleepyHead and ResScan are both fairly close for my data. It seems as though they round off the numbers differently.

That is a hypopnea in the image. It is flatter than those around it. Granted, not by much but enough to register. When it comes to hypopneas, I look at length, not that one was counted.

Hi Paula -

Thanks for your interpretation. I was maybe weighing too much on the supposedly "40 Percent" drop necessary to qualify.
So, any clearly visible flattening is something to look for?

Thanks.

[Sleepster]

Last night in a fit of boredom, I was rummaging through the setup menu on my CPAP machine looking at results.
"Last 7 days - AHI: 0."
Huh?
No apneas?
Not according to Sleepyhead which says I average between 1 and 3 a night.

If you have between 1 and 3 events per (8 hour) night that's a AHI of between 0.1 and 0.4. That's pretty low.

Is your machine set to not display AHI?

For the Sleephead experts: Does Sleepyhead interpret the data or just take what the machine gives it?

It does some of each. When in the daily view look and see how long these events last. If they have a duration close to 10 seconds I can see how it's possible that the machine is not counting them but SleepyHead is. 10 seconds is the cut-off time. If an event lasts less than 10 seconds it doesn't count as an event. Unless you've gone into the SleepyHead settings and told it to count events that last for less than 10 seconds.

[courtney123]

I realize my AHI is low enough to consider CPAP therapy a home run for me - especially since my sleep study showed 30/hour.

I'm just curious about the discrepancy between what the machines shows and SleepHead reports.
It's amazing the things we come up with to drive ourselves crazy :-)

[Sleepster]

My point was that it's so low it's pretty close to the zero that your machine is reporting.