Neural prosthetic devices for quadriplegia

Research into the use of neural prosthetic devices to treat paralysing disorders is expanding rapidly. Functional electrical stimulation of muscles is now used to activate electrically paralysed muscles to restore movements such as the hand-grasp. Sensory feedback signals recorded from peripheral nerves are used to improve the control of functional electrical stimulation systems. Functional electrical stimulation may also be used to stimulate neural circuits in the spinal cord. Electrical recordings from the brain will soon improve patients' control of neural prostheses. Non-invasive electroencephalographic recordings can currently be used to move a cursor across a computer screen. The restoration of near-to-normal limb movement control will, however, require recordings from large numbers of neurons within the brain. Preliminary feasibility has been demonstrated in experimental animals.