Counting of events - need clarification

[kteague]

Was reminded of a very old conversation here but am unable to locate it. My best memory of it was that events can be under reported if the apnea crosses over a machine's reporting time. For instance, if the machine calculates every 30 seconds, and an apnea started 9 seconds before the calculation and continues 9 seconds into the next calculation, it won't be counted as an event even though it lasted 18 seconds. Does anybody remember that conversation or can shed some light on the subject?

[DreamDiver]

Was reminded of a very old conversation here but am unable to locate it. My best memory of it was that events can be under reported if the apnea crosses over a machine's reporting time. For instance, if the machine calculates every 30 seconds, and an apnea started 9 seconds before the calculation and continues 9 seconds into the next calculation, it won't be counted as an event even though it lasted 18 seconds. Does anybody remember that conversation or can shed some light on the subject?

On the S9, there appear to be two SD card logging cycles: one every few seconds for some data and one every couple minutes for other data. It is suggested that if you want accuracy on data reporting for the last few minutes of your sleep period, it's best to avoid unplugging the machine before removing your SD card from the S9. Toggle the blower off. Wait a few minutes. Then remove the SD card for viewing on software. That way, all data are written to the card to the end during the tank cool-down cycle.

What you're suggesting makes sense. Unless there is a power failure or the machine is unplugged before it can finish the logging cycle, all data and their appropriate times should record correctly.

If you have one of the original S9's it's possible you still have the firmware that had a skew in the data that causes things not to match up over a period of days or weeks. To make it all match up again, we ended up having to reformat the SD card every time. Later that year, the firmware was corrected for newer S9's, so that no longer happened. Unfortunately, they didn't upgrade firmware in the older S9's. I hope you've got the newer firmware in your machine.

Chris