While it may eventually become possible to help injured spinal cords regrow their connections, another approach is to compensate for lost function by using neural prostheses to circumvent the damage. These sophisticated electrical and mechanical devices connect with the nervous system to supplement or replace lost motor and sensory functions. Neural prostheses for deafness, known as cochlear implants, are now in widespread use in humans and have had a dramatic impact on the lives of some people. The first neural prostheses for spinal cord injured patients are now being tested in humans. This prosthesis has been experimentally implanted in more than 60 people.
Patients control the device using shoulder muscles.
With training, most patients with this device can open and close their hand in two different grasping movements and lock the grasp in place by moving their shoulder in different ways. These simple movements allow the patients to perform many activities of daily life that they would otherwise be unable to perform, such as using silverware, pouring a drink, answering a telephone, and writing a note. Neural prostheses are complex and contain many intricate components, such as implantable stimulators, electrodes, leads and connectors, sensors, and programming systems. There are many technical considerations in selecting each component. The electronic components must be as small as possible.