ResScan Apnea Events Interpretation

[apnea13]

A detailed graph with a five minute view depicts at 4:46am 18 apnea events. What does this mean? My understanding which I've got to think is more than seriously flawed is that an apnea event involves at least 10 seconds without breathing. Seventeen (18) events at a minimum of 10 seconds each means 180 seconds, or at least three minutes, of not breathing during a one (1) minute period. This can't be.

One minute later at 4:47am there were 11 events, again more than minute's worth.

I'd reallly like to know what this descibed graph means. Can anyone help? Thanks in advance for any time spent helping me.

[RiverDave]

apnea 13,

I think what you are seeing is the duration of the apnea rather than the actual number of events. The apnea is marked in red and the number above it is the duration. To confirm, look at the events graph for the same time period. It should only increase by 1 at 4:46.

Good luck,

[Guest]

I'm afraid I don't follow. You seem to be suggesting an events counting graph with which I'm not familiar in ResScan.

The apneas marked in red above each of which is a number appear in a plot of Events v. Time. What am I missing?

[RiverDave]

My bad, I was referring to the AHI vs Time graph. Sorry about the confusion.

[Guest]

Thanks for your input. My problem stemmed from being too literal combined with ResMed not labeling things correctly. I believe the detailed plot of red apneas and blue hypopneas is mislabed on the ordinate axis. Rather than merely Events, as in number of, I think it should be labeled Duration of Events (seconds).

Would doing so make it right, do you think?

[RiverDave]

What you suggest is true for apneas, but not for hypopneas. For hypopneas I think the purpose the Events graph is to look at clustering and spacing of individual events, rather than any sort of duration analysis.

[billbolton]

I believe the detailed plot of red apneas and blue hypopneas is mislabed on the ordinate axis. Rather than merely Events, as in number of, I think it should be labeled Duration of Events (seconds).

In the ResScan "Detailed Graphs" display there's an axis scale which is defined in terms of the units being measured for all the graph catagories except "Events".

See.... http://picasaweb.google.com/Aussiegrouc ... 4409117010 (thanks Graeme!).

Users of the previous AutoScan software would have identified the scale as Seconds fairly easily but if you haven't seen AutoScan that isn't inituitively obvious.

You should report that as a software "bug" to Resmed!

Cheers,

Bill