Star Trek’s Borg have them. The Bionic Woman has them.

They are computerized devices implanted into the brain. They don’t give super-human strength or the ability to see a flea a mile away in real life. But they’re not science fiction either. Currently these devices either restore some degree of function to a person with a disability or deliver medication when other methods of delivery prove ineffective.

Neurostimulation for Pain Relief
I’ve had a daily mind-numbing headache for the past seven years. I’ve tried pills and radiation therapy for pain relief. Yesterday a new doctor recommended implanting a neurostimulation device into my head; he said it would disrupt the “bad” impulses being fed by my nerves.

Neurostimulation devices, such as the one developed in the 1960s by Medtronics Inc. look like pacemakers that are implanted in the heart. They act like the TENS units that physical therapists use on sore muscles, delivering low voltage electrical impulses to block pain. They are prescribed for patients like me, who have suffered from chronic, intractable pain that hasn’t been treated effectively by other means.

Other forms of implantable devices help to restore function taken away by disease or accident.
In 2003 Brown University and Cyberkinetics Neurotechnology Systems Inc. began work on a device called Braingate. The computer chip monitors brain activity, searching for electrical impulses traveling on neurons, which it converts into computer commands to control either a mechanical arm or a cursor on a monitor.

One of the first people to use the chip was Matthew Nagle, a quadriplegic. After the surgery, Nagle was able to control a computer mouse cursor to switch on and off several home devices.

Restore Sight to Vision Impaired
Implanted computer devices can also help restore sight to the visually impaired. Two types of devices are currently being developed: Epiretinal Implants (on the retina) and Subretinal Implants (behind the retina).

First developed in the 60s, Epiretinal Implants, such as the one being developed by The Dobelle Institute bypass the eye and work in conjunction with an external camera to send electronic data wirelessly to the brain’s visual cortex.

Subretinal computer chips, such as the Artificial Silicon Retina being developed by Optobionics, on the other hand, convert light into photoelectrical impulses to stimulate the cells of the retina.

Speech Disorder
If you have a problem speaking, there may be a brain implant that can help you too. Dr. Philip R. Kennedy, a neuroscientist currently working at Emory University is developing a brain-implantable electrode that will allow those without speech to be able to communicate through a computer interface. 

The electrode is placed in the motor cortex. Brain cells form contacts with the cells, a process that takes several weeks. Neurons in the brain can then transmit an electronic signal when they "fire." The signals are transmitted through wires to an external receiver and amplifier.

Improvements in Technology
Finally, it isn’t difficult to understand that all of these implants work better as improvements are made in computer software.  In their first clinical trial of an epiretinal device, scientists in Bonn, Germany, discovered that implants designed to aid vision are virtually useless without improvements in software to interpret the electronic signals traveling to the visual cortex.

Their first patients could not identify simple shapes. They’re trying to solve the problem by developing software that learns what kinds of signals the brain can identify and interpret.