A closed-loop control system is disclosed for use with an electrosurgical generator that generates electrosurgical energy. The closed loop control system includes a user interface for allowing a user to select at least one pre-surgical parameter, such as the type of surgical instrument operatively connected to the generator, the type of tissue and the desired surgical effect. A sensor module is also included for continually sensing at least one of electrical and physical properties proximate a surgical site and generating at least one signal relating thereto. The system also includes a control module for continually receiving the at least one selected pre-surgical parameter from the user interface and each of the signals from the sensor module, and processing each of the signals in accordance with the at least one pre-surgical parameter using at least one of a microprocessor, computer algorithm and a mapping. The control module generates at least one corresponding control signal relating to each signal from the sensor module, and relays the control signal to the electrosurgical generator for controlling the same. A method is also disclosed for performing an electrosurgical procedure at a surgical site on a patient. The method includes the steps of: applying at least one electrical pulse to the surgical site continually sensing electrical and physical properties proximate the surgical site and varying pulse parameters of individual pulses of the at least one pulse in accordance with the continually-sensed properties.