There was a syfi story called, “The Ring” about a device
like this, go out of an area, immobilized, attempt to
remove immobilized, etc. The hero was eventually in an
accident that removed his finger and so was free of
the device. Don’t know the author.
Jack Vance has a similar story, the Durdane trilogy from the early 70s.
“The land of Shant on the planet Durdane is ruled by a purposely anonymous dictator called the Anome or Faceless Man. He maintains control by virtue of the torc, a ring of explosive placed around the neck of every adult in Shant.”
http://en.wikipedia.org/wiki/Durdane_series
Freegards