A system (10) and method for controlling the inflation, ablation, and deflation of a balloon catheter (1) is provided. The system includes a balloon catheter (1), a console (20) having a pressurized gas or liquid inflation source, and an umbilical system (12) to deliver pressurized coolant to the balloon catheter (1). The system (10) comprises a PID (Proportional Integral Derivative) controller or other pressure-sensing device that monitors the amount of pressure and volume within the balloon catheter. During inflation, the pressure and/or volume of fluid within the balloon (23) is maintained at a target amount in order to provide sufficient mechanized pressure against the desired target region. The system limits the inflation pressure such that a safe quantity of gas would be released should a leak occur. If the amount falls below a certain threshold level, gas or fluid egress is presumed and the inflation process is halted.