I am not sure Eva. I do know there are several kinds. The SCS which is written about alot on the forum, and then there is the morphine pump. A friend of mine has this, and it never gave her problems, just relief. It was inserted into her stomach, and the refill is injected monthly into a spot through her skin. It doesn't hurt her. I am not sure there in a non invasive kind of pump. I will get on line and see what I can find out. If I had a choice, I would have this morphine pump. I was turned down for the SCS for what ever reasons they had. At the time I had no insurance, which was part of the problem. In fact finding any specialist was difficult.
I will try to find out more for you Eva. ginnie