Detecting sudden bladder pressure increases from the pelvic nerve afferent activity

When recording electrical signals from a whole nerve, an increase in the firing frequencies of the fibers contained in the nerve causes an increase in the rectified and time-averaged recorded signal. The latter thus represents superimposed neural activity and can be used for detecting changes in the recorded afferent and/or efferent nerve traffic. The possibility of detecting a fast bladder pressure increase from an increase in the recorded pelvic nerve afferent activity was investigated in this study. Two signal processing approaches were compared: simple discriminant-window thresholding and cumulative sum (CUSUM) algorithm. Both are shown to be able to detect a sudden rise in bladder pressure with the adaptive CUSUM-algorithm being more reliable, but slower.