A thermochromic test body and its relationship with the Effective Radiation Area (ERA) of Therapeutic Ultrasound devices

This paper presents a thermochromic test body to qualitative evaluate the Effective Radiation Area (ERA) of Therapeutic Ultrasound (TUS) devices. The thermal areas produced by three transducers are measured and compared to the ERA of the same transducers measured according to the IEC 61689 standard. A linear relationship was obtained between both kinds of areas suggesting that a quantitative relation can be found and used to easily monitor TUS working conditions.