Image Segmentation for High-Density Surface Electromyography Mappings of Pelvic Floor Muscle Activity of Women with Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) can result in pelvic floor muscle (PFM) overactivity. Current clinical assessment protocols include basic electromyographic assessment of PFM activation; however, they do not provide a comprehensive assessment localized to each region of the PFM. We examined the ability of high-definition features from intravaginal high-density surface electromyography (HD-sEMG) to assess the severity of PFM overactivity in female IC/BPS patients. HD-sEMG was collected from fifteen female IC/BPS patients and fifteen urologically healthy female controls. The 2D mappings of root mean squared amplitude (RMS) at rest normalized by maximal voluntary contraction (resting RMS ratios) were segmented via k-means to identify areas of peak activity and surrounding activity. Female IC/BPS patients exhibited significantly greater resting RMS ratios for peak activity (p=0.0096), surrounding activity (p=0.0003), and average activity (p=0.0016) compared to healthy female controls. Furthermore, the area of peak activity was significantly larger for female IC/BPS patients than for healthy female controls (p=0.0063). Image segmentation of intravaginal HD-sEMG provides a more robust biomarker of PFM as compared to current methods.