Prediction of in situ exposure to ultrasound: a proposed standard experimental method

This article presents results for the prediction of in situ exposure levels using a new experimental technique based on the use of acoustical attenuators. These are made of low-density polyethylene and are placed in the ultrasound beam between the transducer face and the measuring hydrophone. The method has been tested for a number of different ultrasonic fields including those generated by diagnostic medical ultrasonic equipment. Using a tissue-mimicking material as a reference, it is shown that it is possible to use this new method to simulate acoustic pressure levels to within +/- 10% and acoustic intensity and power levels within +/- 20%. The method is proposed as the basis for a standard test method with wide applicability.