Will electrodes inserted in pillowcases and sheets to monitor brain?
If you are having fun asking about the mass production and usage of human brain interfaces, then you might benefit from transhumanism. So, politely put, start taking longevity chemicals like metformin, deprenyl and metoprolol so you might benefit from escape velocity and become a death-optional person. Maybe they could do brain monitoring with reverse dandruff. A person shakes brain monitoring flakes all over their head; each flake is an electrode with an LED on it, and each flake has battery chemistry and circuits printed with like a 9600 DPI inkjet printer. depending on what the microprinted battery/sensor/LED senses it makes the LED emit coded data and the pillow or a camera in the room picks it up The imitation sparkle dandruff gets past the scalp-contact challenges of the pillowcase method.