Surface electromyography and mechanomyography recording: a new differential composite probe.
The objective of the study was to develop a new surface probe for differential mechanomyographic (MMG) and electromyographic (EMG) recording. Differential amplification is commonly used in electromyography to improve the signal-to-noise ratio. A new composite probe was developed with two electrodes (EMG) and two identical piezo-electric membranes (MMG) to be positioned on muscle. The probe had two built-in fixed-gain differential amplifiers: one to amplify the electric signal and the other to amplify the vibration signal. A similar non-differential MMG probe was used for comparisons. Burst muscular activity was recorded using the non-differential and differential probes and was used to test the performance of the two probes in suppressing artifacts of non-muscular origin. Power spectrum analysis of signals from the two probes showed that differential amplification significantly improved the signal-to-noise ratio in MMG recordings and significantly suppressed artifacts (power difference > 90%). The composite probe allowed simultaneous differential recording of MMG and EMG signals from the same muscular site. It recorded muscular activity more efficiently than the non-differential probe and could therefore be useful in studying fatigue and neuromuscular diseases.
Gregori
B
B
Department of Neurological Sciences, La Sapienza University, Rome, Italy.
Galié
E
E
Accornero
N
N
D016477:Artifacts; D004576:Electromyography / Q000295:instrumentation; D004582:Electronics, Medical; D004867:Equipment Design; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D009213:Myography / Q000295:instrumentation*