CURRENT STATUS OF RESEARCH ON BIOPHYSICAL EFFECTS OF ULTRASOUND

This overview of bioeffects of ultrasound presents some key aspects of selected papers dealing with biophysical end-points. Its purpose is t o establish a basis for exposure and dosimetric standards for medical ultrasonic equipment. It is intended to provide essential background r esource material for the medical/scientific community, and more specif ically for scientific working groups. This document was prepared by me mbers of the Safety Committee of the World Federation for Ultrasound i n Medicine and Biology. It was produced as a resource document in resp onse to a request for information by Working Group 12 (Ultrasound expo sure parameters) of the International Electrotechnical Commission Tech nical Committee 87, Ultrasonics. IEC TC 87, WG12 is the working group responsible for generating international standards for the classificat ion of equipment by its acoustic fields based on safety thresholds. Ou r paper is intended to update and supplement information on the therma l mechanism provided in the publication, ''WFUMB Symposium on Safety a nd Standardisation in Medical Ultrasound: Issues and Recommendations R egarding Thermal Mechanisms for Biological Effects of Ultrasound'' (WF UMB 1992). It also provides an overview of trends in research into non thermal mechanisms as a preliminary to the next WFUMB Symposium on Saf ety of Medical Ultrasound when this subject will be examined in detail by a select group of international experts. The WFUMB-sponsored works hop will take place in Utsunomiya, Japan during 11-15th July, 1994. Th e purpose of the meeting is to evaluate the scientific literature and to formulate internationally accepted recommendations on the safe use of diagnostic ultrasound that may be endorsed as official policy of th e WFUMB. It should be noted that the current publication is not intend ed for review or endorsement as an official WFUMB document. It is prod uced as a scientific paper by individuals who are members of the WFUMB Safety Committee, and it therefore represents the opinions of the aut hors. Nevertheless, during the preparation of this document, contribut ions were received from members of the International Electrotechnical Commission Technical Committee 87 as well as many other individual exp erts, and the authors sincerely acknowledge their support.