The neuro-pulse device was a device created by Julian Bashir, Nog and Mikaela Leishman in 2377 that was designed to break Iliana Ghemor's mental hold over Taran'atar. It had to be activated within five meters of the target.
Elias Vaughn carried the device when his team from the USS Defiant pursued Taran'atar into Grennokar on Harkoum. Vaughn dropped the device when Taran'atar attacked him. (DS9 novel: Warpath)
Bashir and Leishman later refined the design. Instead of a dedicated but unwieldy hand-held device, the neuro-pulse could now be triggered through a combadge. (DS9 novels: Fearful Symmetry, The Soul Key)