Surface electromyography and mechanomyography recording: A new differential composite probe

• Published in: Medical & biological engineering & computing Vol. 41; no. 6; pp. 665 - 669
• Main Authors: Gregori, B., Galié, E., Accornero, N.
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.11.2003; Springer Nature B.V
• Subjects: Biological and medical sciences; Electromyography; Electromyography - instrumentation; Electronics, Medical; Equipment Design; Humans; Isometric Contraction - physiology; Medical sciences; Muscular system; Myography - instrumentation; Neuromuscular diseases; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Signal to noise ratio; Technology. Biomaterials. Equipments. Material. Instrumentation; Biomedical engineering
• ISSN: 0140-0118; 1741-0444
• DOI: 10.1007/BF02349974

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.