2.3. Pressure-volume analysis
Derived from the cystometry, the pressure-volume analysis (PVA) of voiding cycles was established by plotting Vive against Pdet (Figure 1A and B)15,16,18. The mean compliance (Cm) during the filling stage was calculated by dividing the infused volume by the threshold pressure (i.e., change in Vive/change in Pdet; ΔVive/ΔPdet). The compliance of the early and the late halves of the filling stage (C1/2 and C2/2, respectively) were respectively done by dividing the change in Vive by the corresponding change in Pdet between the staring and the half as well the half and the end of the filling stage. Post-voided residual volume of a voiding was calculated by the volume difference between the infused volume and voided volume (Figure 1B).