Extract RR intervals from datasets

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[-] Pavel Prikhodko +0 points · 7 months ago

Hi! 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?

Best regards,


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[-] remomueller +0 points · 7 months ago

Hello Pavel, thanks for your questions! I've pinged the team locally, to see who may have insights into your questions.

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[-] Madalena Costa +0 points · 7 months ago

Hi Pavel,

Which specific datasets are you working with?

1) In general, the units for the heart rate variability indices are milliseconds for the time domain variables: AVNN, SDNN, SDANN, SDNNIDX, rMSSD. pNN50 is a %.; the unites for instantaneous heart rate IHR is bpm; the units for the frequency domain variables: total power, ultra-low frequency, very low frequency, low frequency and high frequency power are millisecond square (ms2). The ratio LF/HF is unitless.

2) If you have the ECG signal you can extract the RR intervals using a open-source QRS detector. One is available here: https://www.physionet.org/physiotools/wag/wqrs-1.htm

3) The xml files, if available, contain the sleep stage annotations: 0 for awake, 1 for N1, 2 for N2, 3 for N3, 4 for N4 and 5 for REM. Usually the annotation window is 30 secs. The time of occurrence of the first "non-zero" symbol is sleep onset. The time of occurrence of the last "non-zero" symbol is sleep-offset.

4) The answer to that question depends on the protocol followed by a particular study.

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