Sleepyhead - "Sessions"

I'm curious why SH noted a third session for my data from last night. Session 707 ended when I turned off the machine to use the bathroom, and I did not turn it off again until I rose for the day this morning (I don't use Auto-off). I was asleep at the time that Session 708 ended and Session 709 began in the same instant.

I checked all the charts; there was a break in the lines from 07:45:45 for about a second (hard to be specific because the scale is divided into 12 parts between 7:45:45 and 7:46:00, not 15 parts). I had no events of any type from 7:36 to 8:06; and there was no power outage last night. AHI for the night was 1.78.

This has happened before, randomly. Anyone know why?

Thanks for your input,
Jean

CPAP Sessions Date Start End Duration
PRS1 Session #00000707 2017-10-02 23:12:53 03:01:19 03h 48m 26s
PRS1 Session #00000708 2017-10-03 03:04:27 07:45:46 04h 41m 19s
PRS1 Session #00000709 2017-10-03 07:45:46 08:15:03 00h 29m 17s


Other data:

Philips Respironics DreamStation
Auto CPAPModel 500X120 - J17521232833C
PAP Mode: APAP (Variable)
Min 7 Max 11 (cmH2O)
Date Sleep Wake Hours
2017-10-02 23:12:53 08:15:03 08:59:02
Periodic Breathing 0.00%
Large Leak 0.00%
Clear Airway 0.22
Obstructive 0.00
Hypopnea 1.56
RERA 0.45
Flow Limitation 0.11
Vibratory Snore 0.00
Vibratory Snore (VS2) 1.56
Pressure Pulse 0.78
Breathing Not Detected 0.00%
Statistics
Channel Min Med 95% Max
PressureTherapy Pressure (cmH2O)
W-Avg: 7.32 7.00 7.00 9.00 10.00
EPAPExpiratory Pressure (cmH2O)
W-Avg: 5.67 5.00 5.30 7.30 8.30
Minute Vent.Amount of air displaced per minute (L/min)
W-Avg: 6.33 0.12 6.00 10.12 40.00
Resp. RateRate of breaths per minute (Breaths/min)
W-Avg: 15.03 7.83 16.00 18.00 20.29
Leak RateRate of detected mask leakage (L/min)
W-Avg: 0.21 0.00 0.00 1.00 11.00
Total LeaksDetected mask leakage including natural Mask leakages (L/min)
W-Avg: 19.32 14.00 18.00 27.00 37.00
SnoreGraph displaying snore volume (?)
W-Avg: 0.06 0.00 0.00 1.00 2.00
Insp. TimeTime taken to breathe in (Seconds)
W-Avg: 2.10 0.70 1.94 3.20 7.14
Exp. TimeTime taken to breathe out (Seconds)
W-Avg: 2.05 0.44 1.94 3.34 5.30
Tidal VolumeAmount of air displaced per breath (ml)
W-Avg: 436.67 13.33 360.00 860.00 3596.67

Time over leak redline 0.000%
Machine Settings

PAP ModePAP Device Mode APAP (Variable)
Pressure MinMinimum Therapy Pressure 7.00 cmH2O
Pressure MaxMaximum Therapy Pressure 11.00 cmH2O

Perhaps a momentary power glitch?

Respironics machines have been known to come up with mystery random sessions with no apparent logical reason.
If no power outage to put the blame on then I suspect you had one of those happen to you.
Once or twice probably not a big deal. I have seen some reports where there are 50 or 60 such sessions in one 7 hour night which obviously isn't normal.

My DreamStation also introduces occasional breaks, but rarely more than a few a night. You will also get a break if your power fails. Perhaps also if your power glitches?

You are also guaranteed to get a break at exactly 12 noon, should you happen to be using the machine at that time.

I don't think it matters a whole lot, as long as SleepyHead combines the information correctly, which it seems to do.

If the breaks are occurring too frequently then you may run into problems with the SleepyHead setting of "Ignore short sessions". But in my totally uninformed opinion your machine is defective if you are seeing many short sessions and there's nothing you're doing to cause them.

Thanks for the feedback, all. Since the breaks have occurred only rarely, I'm not going to worry about it. I may mention it to my resp tech when I go in next month.

Jean