An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system including an ultrasonic transducer coupled to an ultrasonic blade. A method of controlling energy delivered to the ultrasonic device may include determining an impedance of the ultrasonic transducer during a transection process, analyzing the impedance of the ultrasonic transducer, profiling the ultrasonic blade based on the impedance, and adjusting a power delivered to the transducer during the transection process based on the profile of the blade. The method may further include pulsing, the power delivered to the ultrasonic transducer, determining changes in tissue characteristics of tissue located in an end effector, wherein the changes in tissue characteristics is determined between pulses, and adjusting power delivered to the ultrasonic transducer based on the tissue changes throughout the transection. An ultrasonic instrument may include components configured to effect the method.
