S9 AHI bug in the Sleep Report screen?

[dave21]

I noticed what I think is a bug in the detailed SLEEP REPORT menu on the S9 where you see AHI, Total AI and Central AI.

For me it seems to manifest itself if my AHI is 0.0 and it's happened a couple of times.

1. Press INFO button and find that your AHI = 0.0
2. Press and hold SETUP + INFO to get into the SLEEP REPORT menu
3. AHI = 0.2, Total AI = 0.2, Central AI = 0.0

So the SLEEP REPORT screen doesn't on some occasions tally for the same night as the INFO screen. I thought it might have picked the 0.2 out of the last part of the previous night but it didn't seem to have.

If I load the data into ResScan it shows AHI = 0.0, AI = 0.0, HI = 0.0 on the summary screen and when you look at the EVENTS graph there are no Apneas or Hypopneas.

So I think there might be a glitch that manifests itself now and again on the SLEEP REPORT screen on the S9 menu unless I'm missing something somewhere. I guess it's possible that the SLEEP REPORT screen is looking at the data in a slightly different way compared to the INFO screen and ResScan 3.10.

Has anyone else been comparing the AHI's religiously on the S9 between the two screens?

Thanks
Dave

[jmelby]

Did you make sure that on the top of the Sleep Report on the S9 display that it was set to "1 Day"? It lets you select a time frame like 1 Week, 1 Month, etc.

[dave21]

Yup, mine was set at 1 day. When I switched it to 1 week or 1 month the figures changed on the Sleep Report screen, and changing them back to 1 day it still showed the incorrect AHI/AI/CI figures I think they might be using a slightly different algorithm to calculate them perhaps, or I know there were a couple of 8 second events but technically didn't get picked up as Apnea's or Hypopnea's and I'm wondering whether maybe at 8 seconds they're being picked up on the Sleep Report screen to highlight this to a doctor. But if that was the case then you'd expect them to be flagged up in the events graph on the ResScan software.

[Torrent]

Dave,

I just experienced this for the first time also, the basic info screen under-reported the events (lower but not zero).
My data from the SD card in Rescan agreed with the detailed summary screen.

I decided to power cycle the S9 and upon reboot the numbers were all in agreement. So this may be a bug.

Torrent

[AirBreather]

Has ResMed made bug-fix PROM upgrade software available via their equipment suppliers in the past?

[dave21]

I've never seen any in the past. If any change is going to happen it's going to be in the sale of new machines having updated firmware unless they identify a very serious bug in whcih case they'll do a product recall similar to the power plug/socket recall they did on the S8 AutoSet Spirits a couple of years ago.