Fig. 1.
Fill (A) and Press (B) protocols for balloons. Pressures (P100-500) were recorded at increasing volumes (100-500ml, respectively). For each protocol, volume was increased to 1500ml, and pre-strain softening pressures (Ppre) were recorded. In the Fill protocol (A), volume was increased to 3000ml to strain soften and peak pressure (Pref) was recorded. Post-strain-softening (Ppost) was recorded after syringe aspiration back to 1500ml. In the Press protocol (B), balloons were compressed 5 times to Pmax and post-strain softening pressures (Ppost) were recorded. Average pressure values for the Fill (C) and Press (D) protocols are presented as a series of pseudo-steady-state pressure values with connecting lines to illustrate their sequence. (E) Normalized pre-strain softening, maximum and post-strain softening pressures for the Fill and Press protocols (* indicates a value significantly different from 1.0, n=5 for each protocol, p<0.05). Post-strain softening pressures were significantly less than the pre-strain softening pressures for both the Fill and Press methods (E, p<0.05).