LOW ENERGY OR MINIMUM DISTURBANCE METHOD FOR MEASURING FREQUENCY RESPONSE FUNCTIONS OF ULTRASONIC SURGICAL DEVICES IN DETERMINING OPTIMUM OPERATING POINT
A method for measuring frequency response is provided that includes supplying ultrasonic energy to an ultrasonic device configured to impart energy to tissue, providing a drive signal and a noise signal, combining the drive signal and the noise signal to create a combined signal, amplifying the combined signal and providing the amplified signal to the ultrasonic device, receiving an output signal from the ultrasonic device and the noise signal, calculating a transfer function estimate based on the output signal and the noise signal, adjusting the drive signal generator based on the calculated transfer function estimate, and determining a phase difference by time aligning the noise signal in the output signal with the noise signal provided.
