Standards development and execution for therapeutic ultrasound applications

Abstract

Therapeutic ultrasound holds great promise in the treatment of a number of different disease states and patient conditions. In bringing these devices to market, the two main considerations are naturally safety and efficacy. Central to the safety evaluation of such devices is the determination of potential hazards through the use of international standards. The International Electrotechnical Commission (IEC), has several standards and initiatives in the area of therapeutic ultrasound, both in the measurement of ultrasonic fields and in safety characterization. To be effective, these standards must not only be technically accurate, but also sufficiently practical that their primary users, namely manufacturers, can properly implement them. This talk reviews the development of standards related to therapeutic ultrasound and also discusses the implementation approaches among different manufacturers. For instance, while diagnostic ultrasound systems can be safely managed with only type-testing, the energy levels from therapeutic systems require that every system be evaluated or calibrated before patient use. Typically, systems undergo detailed sub-system testing, with only limited testing performed on the final product at full energy levels. Assumptions with regard to output linearity are also used to further minimize the difficulties implicit in measurements at high ultrasonic energies.