This pattern is sometimes interrupted – by movements, bad sensor readings and dreams perchance:
I woke up at 0308 when the electrode gel dried up and triggered a string of false positives from the OpenEEG channel. I stayed up for 30 minutes for some Choline and Galantamine and was plagued by numerous false awakenings over the next 3 hours. I also tried out a EV-806A tENS unit at 40 Hz on Fp1 and Fp2 for a few minutes before sleep.
The BPM channel (grey) sometimes climbs of its own accord – that might be the first place to start looking: