Definition

myoelectric signal (motor action potential)

A myoelectric signal, also called a motor action potential, is an electrical impulse that produces contraction of muscle fibers in the body. The term is most often used in reference to skeletal muscles that control voluntary movements. Myoelectric signals have frequencies ranging from a few hertz to about 300 Hz, and voltages ranging from approximately 10 microvolts to 1 millivolt.

Myoelectric signals are detected by placing three electrodes on the skin. Two electrodes are positioned so there is a voltage between them when a myoelectric signal occurs. The third electrode is placed in a neutral area, and its output is used to cancel the noise that can otherwise interfere with the signals from the other two electrodes. The output voltage is processed using a device called a differential amplifier. The output of this amplifier has much higher voltage than the myoelectric signals themselves. This higher voltage, which produces significant current, can be used to control electromechanical or electronic devices.

Myoelectric signals are of interest to the developers of prosthetic devices, such as artificial limbs. The signals can also be used to facilitate the operation of a computer using small voluntary muscle movements, such as blinking the eyelids. A Japanese company is developing a device that picks up speech using the myoelectric signals from the muscles around the mouth. The eventual goal is to create a mobile telephone that can be worn on, or even implanted in, the body.

This was last updated in September 2005
Posted by: Margaret Rouse

Email Alerts

Register now to receive SearchMobileComputing.com-related news, tips and more, delivered to your inbox.
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

More News and Tutorials

  • Clearwire's mobile WiMAX service

    As a mobile manager, you may be excited by the prospect of Clearwire's 4G mobile WiMAX service. But you need to understand the limitations and proceed carefully before making long-term plans that include the use of Clearwire's mobile WiMAX service.

  • Mobile Radio Systems

    The basics of mobile radio design and the performance issues of delivering IP applications over mobile radio networks.

  • Wireless rate negotiations: How to get the best deal

    Wireless negotiations require preparation. Companies must assemble the right team to assess their needs and form a bargaining strategy. With the right game plan, a company can save as much as 50% on mobile voice and data.

Do you have something to add to this definition? Let us know.

Send your comments to techterms@whatis.com

There are Comments. Add yours.

 
TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to: