It is nonsense to claim that PEMF pulsing magnetic fields have a positive or negative field. The same is true for stating that there is a North or South pole magnetic field for pulsing electromagnetic fields because the pulsing field changes polarity the whole time.
When you move a compass from the outside towards the inside and move it again towards the other outside of a coil you can see that the field changes directions. E.g. from North to South, from South to North, and again from North to South etc.
This is also the reason why you do not need to use a specific side of the PEMF coil applicator because the same field extends at both sides of the coil and the reason why you can use with the Curatron one ‘Very high energy coil’ for treatment of e.g. osteoarthritis in both knees at the same time by placing the coil between the knees.
Only static magnets have a North and South pole, also called positive and negative by static magnet sellers. By the way: what side is called the ‘North pole’? The side attracted to the real north pole or attracted to the south pole? Think about this! Most distributors have no clue what they are selling! In a compass the ‘South’ pole of the arrow points to the globe’s north but funny enough is called the ‘North’ pole! I hope I did not confuse you too much...