signals are measured with a High density array of gold plated pins
used as dry electrodes pressed on the skin. No electrode gel is
used because this would short the space between the closely spaced
electrodes (5mm) Because the electrodes are simply pressed on the
skin, very high electrode impedances (up to 1MOhm) can be found.
However, thanks to BioSemi's high quality battery powered front-end,
excellent signal quality is still assured (noise is smaller then
10uVpp) even with these difficult electrodes. The array is developed
as an alternative to invasive methods like needle electrodes. The
array setup provides a lot of extra information about the EMG topography.