Communication between functional and denervated muscles using radiofrequency.
OBJECTIVE
This article focuses on establishing communication between a functional muscle and a denervated muscle using a radiofrequency communications link. The ultimate objective of the project is to restore the eye blink in patients with facial nerve paralysis.


METHODS
Two sets of experiments were conducted using the gastrocnemius leg muscles of Sprague-Dawley rats. In the initial tests, varying magnitudes of voltages ranging from 0.85 to 2.5 V were applied directly to a denervated muscle to determine the voltage required to produce visible contraction. The second set of experiments was then conducted to determine the voltage output from an in vivo muscle contraction that could be sensed and used to coordinate a signal for actuation of a muscle in a separate limb. After designing the appropriate external communication circuitry, a third experiment was performed to verify that a signal between a functional and a denervated muscle can be generated and used as a stimulus.


RESULTS
Voltages below 2 V at a 10-millisecond pulse width elicited a gentle, controlled contraction of the denervated muscle in vivo. It was also observed that with longer pulse widths, higher stimulation voltages were required to produce sufficient contractions.


CONCLUSIONS
It is possible to detect contraction of a muscle, use this to generate a signal to an external base station, and subsequently cause a separate, denervated muscle to contract in response to the signal.


CONCLUSIONS
This demonstration in vivo of a signaling system for pacing of electrical stimulation of 1 muscle to spontaneous contraction of another, separate muscle, using radiofrequency communication without direct connection, may be used in numerous ways to overcome nerve damage.
Jacob
Doreen K
DK
Department of Mechanical Engineering, University of Pittsburgh, Pittsburgh, PA 15236, USA. doreenkjacob@yahoo.com
Stefko
Susan Tonya
ST
Hackworth
Steven A
SA
Lovell
Michael R
MR
Mickle
Marlin H
MH
D000818:Animals; D004558:Electric Stimulation; D006614:Hindlimb / Q000294:innervation / Q000503:physiopathology; D009119:Muscle Contraction / Q000502:physiology*; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013016:Sound