Development of a differential suction electrode for improved intravaginal recordings of pelvic floor muscle activity: reliability and motion artifact assessment.
OBJECTIVE
The purposes of this study were to compare: (i) the reliability of electromyography (EMG) activity recorded from the pelvic floor muscles (PFMs) using a new differential suction electrode (DSE) to the reliability of EMG data recorded using other common electrodes, and (ii) motion artifact contamination of EMG activity recorded from the PFMs using the DSE and the Femiscan™ electrode.


METHODS
With the DSE and the Femiscan™ in situ, at two separate sessions, each of 20 participants performed three repetitions of a maximum voluntary contraction (MVC) of their PFMs, and 10 repetitions of a maximal effort cough. With Delsys® electrodes located over the biceps brachii, each participant performed three repetitions of a MVC. Between-trial and between-day reliability were assessed using several methods. Motion artifact was assessed by comparing the proportion of contaminated files recorded by each electrode during coughing.


RESULTS
The DSE was found to have excellent between-trial reliability, as were the Femiscan™ and Delsys® electrodes. Between-day reliability was good for the DSE, but reliability was higher for the Delsys® electrode and the Femiscan™ electrode. The DSE performed better than the Femiscan™ electrode in terms of motion artifact contamination.


CONCLUSIONS
The DSE has excellent between-trial reliability and performs better than the Femiscan™ electrode in terms of motion artifact contamination. It does not perform as well as the Femiscan™ electrode in terms of between-day reliability--a result that is not unexpected given the localized region from which the DSE records activity.
Queen's University, School of Rehabilitation Therapy, Kingston, Ontorio, Canada.
Nadia
N
Keshwani
Linda
L
McLean
D000293:Adolescent; D000328:Adult; D016477:Artifacts; D003371:Cough / Q000503:physiopathology; D004566:Electrodes; D004576:Electromyography / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008422:Materials Testing; D008875:Middle Aged; D009038:Motion; D009119:Muscle Contraction; D017773:Pelvic Floor / Q000503:physiopathology*; D059952:Pelvic Floor Disorders / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013396:Suction; D013997:Time Factors; D014621:Vagina; D055815:Young Adult