Comparison of acoustic power calibration methods for therapeutic ultrasound transducers using PVDF membrane hydrophone, heterodyne laser vibrometery and radiation force measurements

The acoustic pressure field and power radiated from a high intensity focused ultrasound (HIFU) transducer are of great importance for the safety of the patients in clinical applications. We compared three acoustic power calibration methods for the HIFU transducer. These include a PVDF membrane hydrophone, “brush” target radiation force balance, and heterodyne laser vibrometer. The acoustic pressure and power amplitude measurements had good agreement within a margin of 5 % in the measurable acoustic power range. The advantages and limitations of each of the calibration methods were studied.