An ultrasonic surgical system utilizes a digital control system to generate ultrasonic drive current for transducers that are located in a hand piece and are attached to a surgical scalpel or blade in the hand piece so as to vibrate the blade in response to the current. Each of the pixels comprises at least two sub-pixels, each being composed of at least two colors. A gate width of the first transistor is set so that a change in the edge flank is slowed down, provided that a pulse waveform of the reference clock is not destroyed. The mounting mechanism presses against at least two points of a target portion, e. The system includes an initiation energy source configured to apply an initiation energy to the medium to activate the energy modulation agent. A heater is optionally provided in the lower housing.