Automatic localisation of innervation zones: A simulation study of the external anal sphincter

Repeatability of innervation zone identification in the external anal sphincter muscle

“…Repeatability of the estimation of IZ distribution is also a prerequisite to continuing our research, applying the method on a larger set of subjects and providing clinical evidence of its importance. The repeatability of IZ estimation together with the accuracy of the estimate supported by simulation studies 16 would provide the indication that a single measure is sufficient to get reliable information. This would support the development of a fast, minimally invasive, and reliable method with potential clinical relevance.…”

“…The algorithm discussed in Ref. 16 was used to extract the IZ distributions of the filtered signals. The algorithm detects propagating MUAPs and estimates the IZ, for each detected MUAP, under the channel from which propagation starts, therefore obtaining a distribution of IZ.…”

“…Nevertheless, the application on simulated signals indicated that the automatic method provides a precise estimate of the position of detectable IZs, with resolution related to the IED. 16 Despite these limitations, indications can be provided from the estimated IZ to guide surgery and reduce the risk of incontinence in episiotomy and other surgical trauma. …”

Real time identification of active regions in muscles from high density surface electromyogram

“…The functions a n ðx; tÞ (referred to as basis waveforms in the following) could be simulated using a model replicating as far as possible the investigated physiological system: for example, the geometry of the tissues could be measured (by ultrasound scanning [22] or MRI [15,16,[18][19][20]23]), their conductivity could be taken from the literature [24,25] and the anatomy of the muscle fibres (positions of the IZ and tendons) could be investigated by preliminary surface EMG recordings [8][9][10][11]. Another possible choice is to measure the surface potential resulting from the activity of a specific region: needle EMG can be recorded from different locations and decomposed in order to identify the activity of single MUs [26]; then the surface response related to each identified MU can be estimated by spike triggered averaging [27], obtaining very selective information on the surface EMG response of the activity of specific muscle regions.…”

“…Moreover, as a wide area is considered, many important features (not attainable from needle EMG) can be extracted, e.g. concerning the anatomy of the muscle (positions of IZ and tendon endings [7][8][9][10][11]) and the velocity of propagation of MU action potentials (MUAP) [12].…”