Patent ID: 7850707

Claim:
An ultrasonic surgery apparatus comprising: an ultrasonic chip; a vibration inducing unit which induces ultrasonic vibration to the ultrasonic chip; an aspiration unit which aspirates tissue emulsified by vibration of the ultrasonic chip; a detection unit which includes a pressure sensor for detecting aspiration pressure of the aspiration unit and detects a clogging condition of the ultrasonic chip; a footswitch, having a pedal, for emitting an output signal which is based on a depression amount or a depression position of the pedal; and a control unit which controls at least one of ultrasonic power and a pulse-duty ratio of the ultrasonic vibration based on the output signal from the footswitch and a detection result obtained by the detection unit, wherein the control unit controls the ultrasonic vibration by a first control method when the depression amount or the depression position reaches a predetermined level as well as when the aspiration pressure does not reach the predetermined level, and controls the ultrasonic vibration by a second control method, which is different from the first control method, when the depression amount or the depression position reaches the predetermined level as well as when the aspiration pressure reaches the predetermined level, the first control method keeps the pulse-duty ratio constant regardless of a change in the depression amount or the depression position, and the second control method changes the pulse-duty ratio linearly or in stages in accordance with the change in the depression amount or the depression position.