FIGURE 1. Pressure-volume analyses and derived parameters.
(A) and (B) Pressure-volume analysis established by plotting the intra-vesical volume (Vive) against detrusor pressure (Pdet) of a voiding. The trajectory of pressure-volume data shapes a loop representing a voiding cycle; and the left boundary of the loop indicates the filling stage. (A) The mean compliance (Cm; red) during the filling stage was calculated by dividing the change in Vive by that in the Pdet (Cm=ΔVive/ΔPdet). The compliance of the early half (C1/2, green) and late half (C2/2, blue) of the filling stage were respectively calculated by dividing the half of ΔVive by the corresponding ΔPdet as well as dividing the ΔVive between the end and the half of the filling stage by the corresponding ΔPdet. (B)Post-voided residual volume of a voiding cycle is calculated by the volume difference between the infused and voided volume.