Considerations on noise of electrodes in combination with amplifiers for bioelectrical signal recording.
ABSTRACT Detection of weak bioelectrical signals needs a recording system with a very low system noise. In this paper, the noise of electrodes as well as the influence of different combinations of electrodes and amplifiers on the system noise was investigated. As a first result the electrodes noise is similar to the noise of a passive electronic part with the same impedance. For smaller electrodes a reduction of the electrode impedance will reduce the system noise, also for larger electrodes the electrode itself is not the dominant noise source, so that an improvement of the amplifier is the way to get a better system. A special amplifier was tested with iridium and platinum black electrodes of different sizes.