Multichannel Surface EMG for the Non-Invasive Assessment of the Anal Sphincter Muscle

Abstract

Background/Aims: This work focuses on recording, processing and interpretation of multichannel surface EMG detected from the external anal sphincter muscle. The aim is to describe the information that can be extracted from signals recorded with such a technique. Methods: The recording of many signals from different locations on a muscle allows the extraction of additional information on muscle physiology and anatomy with respect to that obtained by classic bipolar recordings. Multichannel EMG methods have been recently developed for the assessment of the external anal sphincter. An anal probe was used in this study to record signals at different depths within the anal canal during contractions at different effort levels. The plug is 150 mm in length and 14 mm in diameter, holding a circumferential array of 16 equally spaced silver bar electrodes, located at a distance of 20 mm from the probe tip and aligned with the probe axis. Results: Information about localization of the innervation zone, fiber length, EMG amplitude, muscle fiber conduction velocity and single motor unit analysis can be obtained from the signals recorded with the circumferential array by means of innovative signal processing techniques. Conclusions: The type of information extracted from multichannel surface EMG signals cannot be obtained with other currently available techniques. The technological innovation described in this work is promising for a further insight into the investigation of pelvic floor pathologies and rehabilitation treatments.

Evaluation of pelvic floor muscle anatomy and function in women: modern techniques

“…Może być przydatna na przykład, gdy uzyska się właściwą normalizację maksymalnej siły mięśniowej [49]. Ponadto EMG może być interesująca w aspekcie oceny aktywacji mięśni dna miednicy lub koaktywacji wraz z mięśniami otaczającymi [44,[50][51][52], a także w ocenie strefy odnerwienia [53,54].…”

Equalization filters for multiple-channel electromyogram arrays

“…Such montages provide spatial selectivity that can be crucial to the application ,1999Kleine et al, 2000;Merletti et al, 2004;Ramaekers et al, 1993;Rau and Disselhorst-Klug, 1997;Sun et al, 1999). In such systems, the number of possibly useful derived signals (i.e., the number of different combinations of bipolar, LDD and NDD signals) can be too large for practical precision implementation of all possibilities in hardware.…”

Cinemática de quadril, joelho e tornozelo e a atividade muscular de membros inferiores no ciclo completo da marcha de diabéticos neuropatas em diferentes cadências

“…Durante contrações dinâmicas, os dados eletromiográficos são submetidos a alguns fatores intervenientes que contribuem negativamente para a qualidade do sinal, são eles: o grau de não-estacionaridade do sinal, encurtamento das fibras musculares, o deslocamemto do músculo relativo à posição do eletrodo e a grande variabilidade do sinal conseqüente ao rápido recrutamento de unidades motoras (Farina et al, 2001;Farina et al, 2004;Farina, 2006).…”

“…fatores fisiológicos e não fisiológicos comuns a toda aquisição de sinal EMG, como a profundidade do tecido subcutâneo, velocidade de condução das fibras musculares, distribuição das zonas de inervação entre as unidades motoras, crosstalk dos músculos adjacentes, formato e tamanho do eletrodo, distância inter-eletrodo, e a localização dos eletrodos ao longo do músculo (Farina et al, 2004). Este último fator interfere significativamente nas características estatísticas e espectrais do EMG e o não posicionamento ótimo do eletrodo acarretará intepretações errôneas (Roy et al, 1986;Jensen et al, 1993;Li e Sakamoto, 1996;Farina et al, 2001;Merletti et al, 2001;Farina et al, 2002a;Farina et al, 2002b;Farina et al, 2002c;Farina et al, 2004).…”

“…Este último fator interfere significativamente nas características estatísticas e espectrais do EMG e o não posicionamento ótimo do eletrodo acarretará intepretações errôneas (Roy et al, 1986;Jensen et al, 1993;Li e Sakamoto, 1996;Farina et al, 2001;Merletti et al, 2001;Farina et al, 2002a;Farina et al, 2002b;Farina et al, 2002c;Farina et al, 2004).…”