I deal with the heart rate variability analysis. I use your software
SANTIS 1.1 for my scientifc research (non-commercial). This is very
friendly tool, but I have one problem with the Fourier Power Spectrum.
The quantities which I get are very large and they do not correspond to
variance of the signal (by definition spectrum power should equal to the
variance of the signal). Could you please explain me why it happens and
(if you can) could you send me the equations which have been employed
for calculation of FFT spectrum.
Jerzy Sacha, MD
Department of Cardiology
Regional Medical Center in Opole
Al. Witosa 26
fax: +48 77 452 06 99
tel: +48 77 452 06 60