Assessment of common information in surface electromyography recordings with adhesive electrodes and an intravaginal probe

Abstract

[EN] Dysfunctions in pelvic floor muscles (PFM) are a highly prevalent group of pathologies which critically alter daily life activities. Surface electromyography (sEMG) of PFM has emerged as a potential evaluative tool but recordings are affected by interferences of nearby muscle groups. The aim of this study is to assess the association between internal and external sEMG signals in order to better identify the different PFM sources. Four monopolar and two bipolar signals were recorded from the perineum (external recordings), and two monopolar signals with an intravaginal probe in 32 women with vulvodynia.. Cross correlation (CC) and normalized mutual information (NMI) were computed between signal pairs to assess their common information. External monopolar electrodes showed high CC (82 %) and NMI (19 %) among them, probably due to common mode interferences and volume conduction. External monopolar signals on posterior PFM have relevant common information with probe signals of the same side (CC: 55 %, NMI:6.5 %), suggesting that deep PFM activity could be monitored without using intravaginal probes, which are painful for some patients. Little common information was found between intravaginal probe and external bipolar signals, suggesting that deep and surface activity can be assessed separately with these recordings set-ups. These findings can be relevant for the recording and interpretation of sEMG signals when assesing PFM electrophysilogical condition in the clinical management of PFM disorders