I processed an ECG signal using
findpeaks in Octave. Then, I plotted the amplitude of the "peaks" found by that function and got the followinge result (original unprocessed ECG signal on top, simple plot of "peaks" on bottom).
If I analyze the "peaks" signal, I get a frequency of about .07 Hz, which translates to about 14 events per minute. This correlates nicely with breathing rate. Is that really the breathing rate that I found, or am I jumping the gun? I've heard this may be referring to a "DC Drift"?