What maintenance procedures are in place? The TSA turned down the manufacturer's warranty service option.

What regular testing takes place? Who performs this testing?

Why haven't these machines been fully tested like the medical devices that they are?

I know of at least one system - the Therac-25 one of the first systems surveys we completed when I was studying computer science - that jumped through all the hoops we require for medical devices but still managed to harm a number of people.

Can these devices also harm people? I don't know for certain, but I will be happy to let someone else find out.