Geometry assessment of anal sphincter muscle based on monopolar multichannel surface EMG signals

Design of sEMG assembly to detect external anal sphincter activity: a proof of concept

“…Thus, SD recording using these ring electrodes may yield diminishing signals. As action potentials travel between an innervation zone (IZ) and extinction zone (EZ) in the corresponding EAS fibres, an electrical potential distribution is induced on the surface, travelling mainly orthogonal to the anal canal [8] along the circumference of the probe. The recording points of a SD configuration placed at the same distance from the orifice, parallel with EAS fibres, sample this projection of the biopotential as it travels from one point to the other.…”

“…These apply to propagating sEMG components and not the non-propagating components due to the end-of-fibre effect [13]. Contributions involving multichannel sEMG (i.e., multiple SD recordings) have studied different anatomical features of the EAS [5,8,11,[14][15][16][17]. In these studies, linear arrays of rectangular electrodes were used to monitor individual motor unit action potentials to identify the positions of IZs and EZs, fibres alignment with respect to anal canal and different EAS characteristics by densely sampling the surface electrical potential.…”

Real time estimation of generation, extinction and flow of muscle fibre action potentials in high density surface EMG

“…Specifically, the generation involves both a positive and a negative contribution, in different time instants. On the other hand, the end of fibre effect is positive when moving toward the IZ (contribution related to the end of fibre component present in monopolar signals [33]) and negative in the other direction (negative contributions of the extinction of the action potentials beyond the fibre ending were documented in the external anal sphincter muscle, using circular arrays of electrodes following the path of the fibres [34] [35]). Thus, the source term was used to estimate the position of the tendon covered by the grid of electrodes.…”

Multifractal characteristics of external anal sphincter based on sEMG signals

“…All those methods can cause significant stool continence related problems hence proper assessment of anorecatal innervation before and after the treatment can be crucial for prevention and treatment of complications. sEMG enables non-invasive monitoring of the anal sphincter function [4,5,6] and is a very promising method of testing of innervation of muscles. Since innervation deficits are one of suggested mechanisms for severe treatment related complications in up to 40% of rectal cancer patients development of proper innervation assessment methodology is crucial.…”