the FDA applies no regulatory guidelines to this measure to ensure the accuracy of this therapeutic determinant.1 Current FDA guidelines1 do regulate the accuracy of the digital display of total power versus the actual measured total power produced, permitting a ±20% error band. This error band translates into a possible 50% differential in the therapeutic dosing of ultrasound between 2 ultrasound transducers. Secondly, FDA guidelines require that an error band for ERA be reported, but no guidance is provided as to what is an acceptable percentage of error1; most manufacturers report a ±20% to 25% error band for ERA