This technology works by using hair-thin electrodes to read and respond to neurons firing off in the brain. As you can see, the machine is implanted directly into the brain,then connected to a computer and/or another external device.

The device has been successfully hooked up to arms such as this, and has been used to allow a paralyzed man to move a mouse cursor with his thoughts.

This device has been in development for a number of years, with this iteration (allowing for external limb movement)surfacing recently. No price is yet known.