Here is the scenario:
- You are in an environment where there are sources of EM signals that your body will pick up as though it were an antenna via capacitive coupling, i.e. what happens with the 50/60 Hz mains when a person is inside their home.
- There is a hollow cube of metal serving as a Faraday shield with a hole you can stick your lower arm into. The fit is snug enough for no signals to enter through any kind of air gap. Also, although I'm using an arm as an example limb, I'm posing this under the lens of whether or not this would work for any limb in general. If the results would change for whatever reason if it was the head instead, for example, please let me know.
- Within the Faraday shield there are sensors attached to your lower arm that measure how much of the interference signal is able to be picked up via electrodes attached to your skin.
My question is this: if the shield is grounded, would the flush contact between the metal of the enclosure and your skin draw out all the incoming interference travelling along your upper arm so that the sensors inside register none of it? And if not, would placing bracelet-like bands of grounded metal along the length of your upper arm serve to at least lessen the extent to which the picked up signal is able to travel into the enclosure?
The context is that of biopotential sensors, and whether or not a setup like this, however absurd, could be used fruitfully to mitigate mains interference without having to use a shield the size of a whole room.