I have ECG records in *.GDF format, but I don't know what program to use to analyze heart rate variability. I know there's a kubios program that reads this format, but it is available only in the premium version (I am a poor medical student from Russia)
1)is there a free program, analogues of kubios hrv, working with GDF format?
2) is there a program that extracts R-R intervals from the GDF format?
3) is there a way to convert GDF to other formats to be analyzed in programs (edf e.t.c)?
ps. perhaps there are grammatical errors in this text. I used a google translator. I will be very grateful for any help
I have never used the *.GDF format before, but if you are a Matlab/Octave user, there should be functions under the Biosig toolbox http://biosig.sourceforge.net/ that allow you to extract signals from files in that format.
Once you have your ECG signal, you can use the HRV toolkit https://sleepdata.org/tools/physionet-hrv-toolkit to perform HRV analysis. I also like this toolset: http://www.robots.ox.ac.uk/~gari/CODE/ECGtools/ for Matlab if you prefer.
I hope this helps!