Electro-muscular constrictor
From Tardis Wiki, the free Doctor Who reference
The electro-muscular constrictor was an item of the Master. It had to be worn around the wrist of a humanoid target, thus giving to him complete control over the hand of the victim, remote-controlled through a box.
He used it on Logopolis, on Nyssa, trying to force her to strangle Adric. (TV: Logopolis)
