System and Method for Tissue Sealing

A method for fusing biologic tissue comprising the steps of:

• providing an electrosurgical instrument including:
• at least one active electrode adapted to apply electrosurgical energy to tissue;
• and
• a pair of jaw members configured to grasp tissue;
• providing an electrosurgical instrument adapted to supply electrosurgical energy to the at least one active electrode, the electrosurgical generator including:
• impedance sensing circuitry configured to measure impedance of tissue;
• providing a processor in operable communication with the electrosurgical instrument;
• closing a pair of jaw members of an electrosurgical instrument about tissue;
• applying electrosurgical energy to tissue from an electrosurgical generator;
• determining whether tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance;
• generating a target impedance trajectory as a function of measured impedance and desired rate of change based on the tissue reaction determination, the target impedance trajectory including a plurality of target impedance values;
• determining whether a final tissue impedance value was reached;
• responding to a determination that a final tissue impedance value was reached by:
• interrupting the application of electrosurgical energy to tissue;
• cooling the tissue during a cooling period;
• and
• indicating tissue fusing was successful;
• responding to a determination that a final tissue impedance value was not reached by:
• interrupting the application of electrosurgical energy to tissue;
• indicating tissue fusing was unsuccessful;
• and
• releasing the jaw members from tissue.