Corpo de prova termocromático para verificar área de radiação eficaz em ultrassom fisioterapêutico

Abstract

Nowadays physiotherapeutic ultrasound is largely used to treat different clinical conditions. However to the safety use of the equipment, the nominal intensity versus measured intensity curve must be known, and, thus, the effective radiation area (ERA) and output power need to be known. The ERA determination according to Norm is a specialized procedure not easily available, thus while the power output of transducers require radiation force balances. Test-objects made with thermochromic materials have been developed as a low cost option with the objective of verifying the quantitative relation between the heated area of thermochromic test-object and the ERA of ultrasound transducers applied to physiotherapy. The protocol developed by Costa (2015) was used, with the physiotherapeutic equipment exciting the transducers during data acquisition in the test-objects. Linear and quantitative relationships were obtained, showing that it is possible to estimate the ERA from the thermal spot. It also opens the possibility of periodic verification of devices using the proposed thermochromic test-objects, observing ERA variations and hot spots on the transducers.