An automatic measurement system using piezoelectric hydrophone for the three-dimensional ultrasound field distribution

High intensity focused ultrasound (HIFU) as a non-invasive and minimally invasive treatment provides a green physical treatment options for clinical cancer therapy in addition to surgery, chemotherapy and radiotherapy. The 3D acoustic field distribution of HIFU is not only the key parameter for evaluating the quality of the transducer, but also an important indicator of the security and efficiency of HIFU system. An automatic measurement system using needle hydrophone was introduced in this paper. According to the national standard, the field distribution of ultrasound and key parameters of the focal region were measured by the system. A variable step length scan strategy is proposed. The sound field distribution of measurements results and theoretical simulation were compared and the results showed that the measurement results from the focused sound field measurement system using piezoelectric hydrophone are accurate and reliable. The scanning time is greatly reduced with no significant sacrifice of the spatial resolution. The proposed system with variable step length is an easy, quick, and reliable approach to calibrating focused ultrasound with satisfactory accuracy.