Impedance Spectroscopy Method to Detect Pelvic Floor Muscle Damage—A Feasibility Study

Impairment of the pelvic floor muscles and fecal incontinence affect 5–10% of the adult populations of European states. The most common cause is perinatal obstetrical anal sphincter injury (OASI) resulting from vaginal delivery. There is no method for screening in the period immediately after delivery. Diagnosis is limited to physical examination. The gold standard, transanal ultrasonography and manometry, can be performed after a few weeks, whereas clinical practice requires that injury be detected as early as possible for optimal treatment. Therefore, we would like to validate an alternative technique, impedance spectroscopy. The aim of the study is to analyze the accuracy of problem detection within the 3–1000 kHz frequency range in 3 radial positions. 22 females (10 issued and 12 included in a control group) were engaged. Impedance moduli and phase shifts were estimated using a bipolar impedance spectrometer along with a specific anal probe. We calculated parameters assessing different subranges of analyzed frequencies and treated them as input vectors for detection. Accuracies were estimated for Naive Bayes, Random Forest, Support Vector Machine and Quinlay’s C5.0 models. We performed recursive feature elimination to find the most significant subranges of frequencies. An accuracy of 86.4% was observed for the Random Forest technique and entire set of considered parameters. It appears that impedance spectroscopy allows assessment of problems with pelvic floor muscle (particularly OASI), directly after vaginal delivery and faster and easier than gold standard methods.