This example shows the inflation of the bladder using the pole zero law.

The pole zero material parameters were originally created to model the heart muscle constitutive properties. The bladder is much more compliant in fully undeformed shape, therefore the material properties for the heart are only a first approximation of the bladder properties. Allowing for the extra compliance by moving out the poles and increasing the curvature makes the computation unstable and has to be done with care. This example uses the default properties (more compliant than the current heart parameters) as the constitutive parameters. However because of the bladder instability when fully collapsed, the starting point of this example has the bladder partially full. This simulates a patient in urinary retention.

The start and end points of the inflation are shown in the figures below.