This International Standard specifies: – the essential non-thermal output characteristics of ultrasonic surgical units; NOTE 1 – One of the parameters of interest is output acoustic power. This standard addresses only the lowfrequency (under 100 kHz) component of the total delivered energy. The high-frequency component, which probably relates to cavitation developed at the tip, is not addressed (see A.4). – methods of measurement of these output characteristics; – those characteristics which should be declared by the manufacturers of such equipment. NOTE 2 – In the interest of clarity, this standard does not address all of the complex surfaces and shapes possible for applicator tips. A straight tubular shape is used in the description of the parameters and measurements to be made. It is left to the user of this standard to adapt the basic methodology described to more complex designs if required. This International Standard is applicable to equipment which meets the requirements of a, b and c below: a) ultrasonic surgical systems operating in the frequency range 20 kHz to 60 kHz; and b) ultrasonic surgical systems, whose use is the fragmentation or cutting of human tissue, whether or not those effects are delivered in conjunction with tissue removal or coagulation; and c) ultrasonic surgical systems, in which an acoustic wave is conducted by means of a specifically designed wave guide to deliver energy to the surgical site. NOTE 3 – Examples of these types of systems are surgical aspirators, intracorporeal lithotripters, end-cutting devices etc. This International Standard is not applicable to: – lithotripsy equipment which uses extracorporeally induced pressure pulses, focussed through liquid conducting media and the soft tissues of the body; – surgical devices used as part of the therapeutic process (hyperthermia systems); – surgical devices whose acoustic application areas are not at the end of a longitudinally vibrating applicator tip and therefore would not fit the monopole model used in this standard. This International Standard does not deal with the effectiveness or safety of ultrasonic surgical systems. NOTE 4 – Throughout this standard, the term accuracy means the overall uncertainty expressed at the 95%confidence level.