Figure 2: An overlaid graph of NIRS parameters zeroed to S (uroflow start) in an asymptomatic 43-year-old man. An increase in total hemoglobin (tHb) is seen as uroflow starts due to an increase in oxygenated hemoglobin concentration (O2Hb); this trend continues throughout voiding while HHb remains stable. This implies an increase in the provision of oxygenated blood to the detrusor as the bladder empties, as occurs in healthy striated muscle during contraction.