Fig. 4.

Simultaneous data (uroflow, EMG, voided volume, and NIRS pattern of chromophore change in a child with symptoms of non-neurogenic lower urinary tract dysfunction. Following permission to void an initial increase in ΔtHb occurs due to an equal increase of ΔO₂Hb and ΔHHb; a sharp decrease in ΔtHB is then evident predominantly due to a fall in ΔO₂Hb that continues as uroflow starts, periodic increases in ΔtHB/ΔO₂Hb occur, but the trend is negative during voiding particularly from 23 seconds, while ΔHHb remains stable. This chromophore pattern implies a failure of oxygen supply to meet demand following permission to void followed by hemodynamic fluctuation with variations in the availability of O₂Hb and total blood volume in the detrusor during voiding.