Phantom limb sensations can now be used to control a computer

Phantom limb is the sensation that an amputated limb is still attached to the body and is moving appropriately with other body parts. Approximately 60 to 80% of individuals with an amputation experience phantom limbs.
Phantom limb sensations are due to reorganization in the somatosensory cortex. So cortical region earlier catering to the arm, starts receiving inputs from the face. This has been demonstrated –  Stroking different parts of the face leads to perceptions of being touched on the missing arm.
Now a company called Rovi Guides has patented an invention that detects the motions of a non-existing arm and uses it to control operation of a computer. The invention exploits the fact that muscle control of arm originates in the brain.
When an arm is completely missing, there is no way to detect muscle activity. But by sensing activity in certain regions of the brain, the movements of the phantom arm are detected. These movements are then recognized and used to perform certain operations like controlling volume on a media player. When the amputee performs a movement with the phantom limb even with the missing prosthetic device, a unique EMG signature is generated. By sensing and recognizing this EMG signature, operations of a computer can be controlled.
Patent Information
Publication number: US 9294802
Patent Title: Gesture control based on prosthetic nerve signal detection
Publication date: Mar 22, 2016
Filing date: Jan 30, 2015
Inventors: Michael R. Nichols; Danielle Larson;
Original Assignee: Rovi Guides, Inc.