I've been studying brain waves for a while and I want to do a project like this for educational purposes, manufactured TENS devices do not have an "audio input" they are programmed with an operating pattern, it would be necessary a circuit that "receives" the analog signal from the output sound...
I was going to a chiropractor who used a TENS machine in my treatment. The last visit, the electrodes were “crossed” - one of each pair on my left/right shoulder, while the corresponding electrodes were on my right/left hip.
I started to experience strong chest pain on my left side. I couldn’t...