I'm doing a comparison of heart rate variability in awake and sleeping humans and your research interests me. When working with your dataset, I'm having some questions:
1) what is the dimension of the signal H. R.? Is it milliseconds?
2) is it possible to extract RR-intervals from your data?
3) is it possible to know the time of the sleep/awake?
4) at what point of time the recording starts? When the surveyed goes to sleep or turns off when light?