Just to clarify a bit regarding the lib and actual hardware for this kind of treatment; the waveform used is bipolar, which means it goes from 0 to +50v back to 0 and then -50v and so on. This is not what SimpleFoc does, so don’t put your coils on the head just yet. To make this kind of waveform I suppose you need a specific PSU or circuit taking these voltages into account.
Here is the patent application (expired), showing the circuit used.
Edit: I Think there is some confusion regarding this negative voltage. Why would you apply a negative voltage to a coil? The goal is to change the direction of the magnetic field. So in a sense, by making the electrons flow the opposite way, compared to what it was, is flipping the potential. What they wish to achieve is to excite the tissue/cell ions by pulsating magnetic fields “T-PEMF” (Pulsating Electro Magnetic Field). So how do one make a magnetic field pulsate. One way would be to turn it on an off in “one” direction, another way would be to flip the direction.
Aka AC wave form