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Re: Spikes in Tidal Volume
Posted: Mon Aug 19, 2013 6:44 pm
by avi123
john5757
if you can show expanded time sections of your Tidal Volume graph then we could see the length of time that those "Spikes" lasted.
Here I use my own data to show it.
The followings are non expanded graphs:
You can see that at 23:56 and 23:57 I had Tidal Volumes (TV) jumps, doubling the TV values that looked like Spikes but actually each lasted several seconds. It's possible that I was not yet asleep at that time.
Also notice that while your Spikes were sort of organized, time wise, my were more at random during the whole night. Check it in un zoomed windows.

Re: Spikes in Tidal Volume
Posted: Mon Aug 19, 2013 7:27 pm
by john5757
My spikes are definitely spikes very sharp and very short
Here I expanded one of the spikes.
I do not think that is a great sign and I noticed that the flow rate is more flat at this point when this happens. Still kind of a mystery and could be a reason that I am a bit tired when waking up.
Re: Spikes in Tidal Volume
Posted: Tue Aug 20, 2013 12:08 am
by Todzo
john5757 wrote:My spikes are definitely spikes very sharp and very short
Here I expanded one of the spikes.
I do not think that is a great sign and I noticed that the flow rate is more flat at this point when this happens. Still kind of a mystery and could be a reason that I am a bit tired when waking up.
Arousal during spike - very likely!
Re: Spikes in Tidal Volume
Posted: Tue Aug 20, 2013 9:28 am
by avi123
Those "Spikes" in the graphs could be artifacts from the measuring instruments, and thus could be ignored.
Check this:
What Qualities Must Be Preserved In Editing?
If you use respiration data for transfer function spectral analysis of respiratory sinus arrhythmia it must be calibrated carefully. The most important quality to preserve is the cyclic breathing pattern so that respiratory rate can be estimated correctly. Many irregularities in wave height and frequency can be ignored if they conform to a general cyclical pattern and if the averaging over a minute or so will overcome much of the misestimation error.
Be conservative when editing baseline shifts and movement artifacts. Areas you exclude are interpolated as straight lines. Therefore, exclude only clear artifactual spikes, but do not exclude small baseline shifts and slower ‘unusual’ phenomena.
Source:
http://www.anslab.net/static/helpprofes ... raphy.html
Re: Spikes in Tidal Volume
Posted: Wed Aug 21, 2013 6:47 pm
by john5757
Mine was not a artifact. I came to the conclusion that I am gasping during sleep and not know it.
Here is the another graph of the flow rate during this sharp tidal volume peak
