Recently I met with a Medtronics rep and asked her why we’re told not to take a pump go through the full body scanners (FBS). Her answer was that Medtronics has not fully tested that scenario yet and out of an abundance of caution recommends avoiding the scanner and the conveyor belt x-ray machine.
My physics background makes me wonder if there is a real danger in the FBS due to the oscillating electromagnetic fields it relies on for operation, they emit millimeter length EM waves. An oscillating field will create a small current flow in electronics which may cause the motor to move, jam or malfunction in some other manner. I’d be surprised if the current is large enough to damage the electronics but it’s not entirely impossible.
I personally am not willing to risk a pump malfunction on a trip just to avoid an airport pat-down, especially if I get a cigarette when it’s over. 
Wheelman