It's like a pacemaker for the brain. The lead/wire is wrapped around the Vagus Nerve in the middle of the neck, but the incision is made on the side of the neck. It is than connected to the battery, which is placed in a flap of skin( which they re-open when they replace the battery every 3-5 years or longer depending on how high or low the VNS is set). For me the battery has lasted 3 years the first time, 6 years second time I had it replaced. Battery replacement is only a Day Surgery. The first time you get a VNS installed you are totally out though. This procedure is done by a neurosurgeon.
Vagus nerve stimulation I have one it tickles your throat and changes your voice each time it goes off.
Vagus Nerve Stimulator. I actually have one!