EMG: Electromyography Signal Control

Most Assistive Technology switches require a specific physical muscular movement to work - eg downward movement of a finger on a press switch such as a Jellybean, or movement of the mouth muscles on the sip-and-puff straw of a pneumatic switch, or precisely controlled movement of the eyes. This requires both sending precise nerve signals from the brain to the switching muscle, and accurate response by that muscle to make the switching action. These may be thought of as physical switches.

Those nerve-based signals can be measured in the muscle in a process called electromyography (electro for the electric characteristic of the nerve signals; myo from the Latin word for muscle; and graph for the recording and display of the signals). The value or size of each of those signals comprise the electromyography results or EMG values, and are measured in microvolts (?V) or millionths of a volt. NeuroSwitch uses those EMG values to provide its comprehensive range of communication and control.

Using EMG as an Assistive Technology switch is like tapping a telephone line to intercept the message before it comes out of the telephone (in this case, the switching muscle). Instead of requiring the muscle to function properly - to activate a press, proximity, pneumatic or eye switch - an EMG switch needs only to measure the very tiny voltage inside the muscle. This use of electromyography enables a person with profound disabilities to use NeuroSwitch to communicate, and to control a range of computer programs and application.