The word "occipital" refers to a nerve in your head. It controls sensation in the scalp. The "nerve stimulator" obviously refers to the device put in you and what it does. Therefore there are more than one type of nerve stimulator. There are peripheral nerve stimulators, spinal stimulators, trigeminal stimulators, etc. They are all basically the same device...they are just named for the nerve they work on.
The nerve stimulator is made up of a battery and some long wires (called "leads"). The battery is 2" x 2", and about half an inch thick. So it's about the size of an Oreo cookie (well, the cookie part anyway, not all the filling and the other cookie). The battery is implanted somewhere in your body. For occipital nerve stimulators, it's usually implanted in the pocket of fat right below your collarbone, so that you're really lucky and get to be a 28 year old with a pacemaker-type scar. Oh wait, that's just me. They can be put in your back, but the chance of lead displacement is higher then because there is a higher amount of movement through your back. Personally, I'd rather not have the leads move and have to deal with that so I'm okay with the pacemaker thing. The battery lasts anywhere from 10 to 25 years, depending on how much you use the stimulator. I figure that by the time I need my battery changed they'll have developed one the size of a paperclip. I wonder where they'll put that. The leads are placed in your head via a small incision, between your scalp and skull. Then they are tunneled under the skin with a hollow needle and adjusted to cross the proper nerves. They send an electrical signal that your nerve senses...it's a tingling sensation. This sensation blocks the nerve from sending a pain signal. Pretty straightforward concept, if you ask me. Apparently the stimulator can have up to 4 leads attached to it. There are two places to connect to the battery, and you can join two wires together via a connector (as shown in the photo at left), for a maximum of 4. From the incision site, the other end of the lead is tunneled under the skin on the neck and shoulder down to the battery in your chest. So everything is just under the surface, and is fully embedded in your body.
To control the stimulator, you have a remote control, which I hear are very expensive to replace if you lose yours. You only get one with your implant. It's a bit bigger than an average cell phone. With this remote you can turn the stimulator on and off, control stimulation strength and speed, and control all these things on the individual wires. Unfortunately you have to hold the remote control right over the battery to get it to function, it's not exactly like a TV remote that you can point and shoot from across the room. But then again maybe that's a good thing, in case it gets in the wrong hands. This is also another reason to have the battery placed in your chest as opposed to your back where it would be quite hard to reach.
The battery is rechargeable. Recharging frequency again depends on how much you use the stimulator, but typically it's a good idea to recharge every other day. The charger has to be held over the battery as well, just like the remote, but only takes about 20 minutes to recharge. So if you just sit/lay and read a book or watch TV while you do it, it's not a big deal. Maybe I can tell my boss I need to "recharge" every day around 2pm and get a nice medically excused nap everyday. Hmm, I might be on to something.
As for restrictions, well, they are about the same as anyone with a pacemaker. You'll set off metal detectors, but they give you a medical card to carry for that reason. You can't go in an MRI. No ultrasounds in the vicinity of the stimulator (my doctor said nothing above the waist), no muscle stimulators (like some chiropractors use). You have to stay away from welding machines (not sure why but my experiences with welding are limited to watching my boss weld together some rebar in a garage about 5 years ago so I'm not exactly a leading expert on the subject). I also know a gal who has a spinal stimulator and says she sets off the burglar alarms in Wal-mart, but I don't think of that as a restriction, I think of it as retribution...a way to annoy Wal-mart the way it annoys me. See, there are many benefits of a nerve stimulator...probably more than you even thought!