Heart rate time series for 5 different groups of healthy subjects can be found in text form in the subdirectories of this one:
- chi: Chi meditation group. There are two time series for each of the eight subjects (C1, C2, ... C8), denoted by record names with the suffix pre for the pre-meditation period and med for the meditation period. Each series is about one hour in duration.
- yoga: Kundalini Yoga meditation group. As for the Chi group, there are pre and med series for each of the four subjects (Y1, Y2, Y3, Y4). Durations range from 17 to 47 minutes.
- normal: Spontaneous breathing group (N1, N2, ... N11). Volunteers were recorded while sleeping. Durations are 6 hours each, except for N3 (4.6 hours).
- metron: Metronomic breathing group (M1, M2, ... M14). Volunteers were recorded while supine and breathing at a fixed rate of 0.25 Hz for 10 minutes.
- ironman: Elite athletes (I1, I2, ... I9). Subjects participated in the Ironman Triathlon; the recordings were obtained during sleeping hours before the event. Durations range from 1 to 1.7 hours.
A detailed description of these 5 groups can be found in the original article (reference below).
For each recording, in addition to the text file, there are (in this directory) a binary annotation file (with suffix .qrs) and a text header file (with suffix .hea), written in the standard formats used for other PhysioBank databases. Each set of three files has a common record name composed of a group identifier and a subject identifier (number). Although all beats are marked normal in these recordings, there may be small numbers of abnormal beats.
The text files contain the same information as in the annotation and header files, and may be reproduced from the annotation and header files using the program ihr, available here. The first column in each text file is the elapsed time since the beginning of the recording (in seconds), and the second column is the instantaneous heart rate (in beats/minute). Note that these recordings generally contain lengthy unannotated intervals preceding the first annotation.
Peng C-K, Mietus JE, Liu Y, Khalsa G, Douglas PS, Benson H, Goldberger AL. Exaggerated Heart Rate Oscillations During Two Meditation Techniques. International Journal of Cardiology 70:101-107, 1999.