Fig. 4

Experimental P–V and d–V relationships for valvuloplasty balloon free inflation. In curve 1, pressure starts increasing in correspondence of the nominal volume and diameter as reported in the device specifications (V ₀  = 21 ml and d ₀  = 22.7 mm); curves 2 and 3 show a progressive increment of the nominal values of both volume and diameter (V _0,2  = 21.6 ml, d _0,2  = 22.9 mm and V _0,3  = 22.0 ml, d _0,3  = 23.2 mm)