How are EMG channels calculated?
I see a lot of different electrode systems. OpenBCI uses electrodes to calculate each EMG channel and a common reference ground. Is the signal for each channel (abs(electrode1 - electrode2-ground))? I have also seen systems where there are two electrodes for each channel but no common ground. In these systems is there a separate ground for each system ? How are the channel value calculated?
Devices like the myo armband use three electrodes for each channel, with a separate ground for each channel, is the signal for each channel (abs(electrode1 - electrode2-ground))?
Which system is the best?
I'll really appreciate any information or references I can read more about this