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I am building a hobby EEG and I am interested in quantifying how effective are the various noise reduction techniques.
The basic circuit would be two electrodes going to an instrumentation amplifier. Then the signal goes to various filtering stages and then to a final "mundane" amplifier. I am interested in noise reduction before the filtering. Here are the steps that I am considering (hopefully this can evolve into a community wiki).
- Adding a right leg electrode directly linked to the ground of the circuit. (against 60Hz hum)
- Adding a driven right leg electrode for common mode rejection. (against 60Hz hum)
- Adding passive low pass filters in front of the inputs of the instrumentation amplifier (see here). (against DC difference between the electrodes and bias current from the inputs)
- Faraday cage (against 60Hz hum)
- Shielded cables for the electrodes (against 60Hz hum)
Are there any technical manuals discussing these approaches? Could you share your knowledge about the effectiveness of each approach? Could you suggest other approaches?