How does my CPAP measure sleep?

[karaoke dokey]

I've searched, but I have not found ....

While I'm sure that the answer will be beyond me, I'm curious as to how my device measures my sleep. Its rather stingy, I find, barely granting me 5 hours out of an 8 hour session.

Resmed S9 Elite, full mask, 7cm

many thanks

[Wulfman...]

I've searched, but I have not found ....

While I'm sure that the answer will be beyond me, I'm curious as to how my device measures my sleep. Its rather stingy, I find, barely granting me 5 hours out of an 8 hour session.

Resmed S9 Elite, full mask, 7cm

many thanks

That's not much information to go on.
WHEN (as in what hours) are you using the machine? Most machines record a "day" as Noon from one day to Noon the next day.
If your sleep is "straddling" that Noon time, it's not going to record the rest until the next day.
Most of them need a certain amount of time to conclude that you're done using the machine for a particular day. If you're checking your data before that time (usually an hour), it probably won't be complete.
And, if the newer (ResMed) machines work like the older ones, if you check your data after Noon, it wipes out that previous data from the LCD information.


Den

.

[karaoke dokey]

Noon to noon? Good grief, I'm a day sleeper.

[Goofproof]

In reality it's not the job of a XPAP machine to measure your sleep. It measures the time the machine was used, correctly and incorrectly both. If it collects full data and you have the correct software, you can figure when you were asleep by the way the data looks.

In the sleep lab, the wires they hook up do measure your sleep by brain activity. Jim

[Wulfman...]

Noon to noon? Good grief, I'm a day sleeper.

Some people are. (many) Years ago I worked shift work, so I can relate.

If you're not using software like Sleepyhead, get it and use it. It'll tell you what you need to know.
If you don't know how to find it, it's in Pugsy's first link in the Announcements section on the first forum page.

Den

.

[karaoke dokey]

Helpful stuff, thanks

[yaconsult]

The machine has NO idea if you are awake or asleep. It monitors the breathing of the person connected to it and makes adjustments to try to keep the airway open. Depending on the machine, there is a certain time of day that it rolls over and counts the time in use as being on the next day. This shouldn't make any difference as it always does this at the same time each day. So any hours of use missing on one day will show up on the previous or next day.

[Pugsy]

The ResMed machines have a clock that the patient can set so that day sleepers won't have their sleep sessions broken up by the Noon reset of the data.
The default for the 24 hour reset is 12 PM...Noon as that is when most people are awake and this is when the machine resets usage hours to 0. Normally not an issue but kinda messes up the usage hours when a person sleeps past noon or goes back to bed after being up for a short while after 12 PM.

You could set the machine clock so that 12 noon is really 6 PM (or whenever you are always awake) if you wish but bear in mind that the software report time of usage will be off but the sleep sessions won't be broken up. A lot of shift workers do this.

But it isn't critical because eventually the sleep sessions will reflect the total amount of usage that is easily seen on the software reports...it's just the LCD screen that could reflect only the most recent session or usages past the cut off at 12 Noon.