Fig. 2.

Changes in chromophore concentration in an asymptomatic adult experiencing voiding delay following permission to void. Spontaneous movements by the subject at 19 and 98 seconds [bold arrows] displaced the data baseline; these data points have been removed [broken line] for clarity of chromophore trends. Changes in blood volume (Total Hb) are evident indicating hemodynamic change; the trend of increasing ΔHHb indicates rising oxygen consumption; uroflow starts after an abrupt fall in ΔHHb that follows a sustained increase in ΔtHb/ΔO₂Hb. Isovolumetric bladder contractions probably occurred during ongoing urgency to void, while bladder volume remained constant.