Figure 1. Example timeline of bladder testing protocol.

The events fixed in 15 minute intervals are shown in solid lines. Ultrasound scans dependent on subject descriptors of bladder capacity are shown in dashed lines. At the beginning of the study, all of the subjects voided, began hydration and underwent a baseline scan. Every 15 minutes subsequently, subjects indicated urgency and pain on a VAS scale. Once the subject had attained first sensation of bladder distension, an ultrasound scan was performed. Additional scans were performed as the subjects reached the prespecified, verbally anchored cystometric thresholds. If study was not completed by 45 and 60 minutes, the subject was instructed to drink an additional 10 oz of water at each point. The duration of the study was capped at 120 minutes.