Bistatic passive mapping of the field distribution of single element transducer in agar phantom

High intensity focused ultrasound (HIFU) can provide a means of noninvasive ablation or hyperthermia of tissues such as tumors. Real-time monitoring of the progression of the field distribution of the HIFU transducer during treatment is important for localizing the intersection of the beam with the tissue. By continuously visualizing the HIFU field in a tissue, better positioning of the HIFU beam for therapy can be obtained during treatment. To visualize the HIFU field in a tissue, a passive listening technique was employed using beamforming approaches and a linear array system co-aligned with the HIFU source. The passive array made use of the weakly scattered signal from the medium to reconstruct the field pattern of the HIFU field in the medium.