scope:

These recommendations apply to apparatus designed for therapeutic use. Such apparatus consists of a generator of high-frequency electric energy and a transducer, usually a disk of piezo-electric material, for converting this to ultrasound. The transducer is housed in a holder designed for local radiation of the ultrasound to the human body. The transducer and associated parts with their housing are known as the treatment head. These recommendations provide suitable methods for calibrating the intensity and distribution of the ultrasonic beam produced by this apparatus and should enable both manufacturers and supervising agencies to provide proper labelling as set forth herein. These recommendations relate only to ultrasonic therapeutic equipment employing plane circular transducers in accordance with present practice. If future developments should lead to other acceptable transducers, appropriate provisions will be added to these recommendations. These recommendations relate only to physical characteristics of the apparatus. Therapeutic value and methods of use are not considered.