Monofilament stimulator
A monofilament stimulator was a component of an electro-dynamic probe. With the proper modifications, it could be used to manipulate neurotransmitter levels in a Human brain.

During his 2374 investigation into Kovin's possible assault on Seven of Nine, The Doctor saw Kovin's electro-dynamic probe with a monofilament stimulator as corroboration for Seven's story. ()

de: Monofadenstimulator
Medical equipment