High intensity focused ultrasound

HIFU transducers

High intensity focused ultrasound (HIFU) holds promising future for non-invasive surgery. We recently developed a dual frequency HIFU transducer (Figure A) with two identical active layers (PZT-2) bonded together, which broke the symmetry of the vibration boundary conditions and generated 1.5 MHz and 3 MHz ultrasonic waves with almost the same amplitude (Figure B). Acoustic power outputs of the single or dual frequency waves were calibrated with an acoustic power meter. The tissue ablation with 6 W acoustic power output from this transducer illustrated the higher heat generation efficiency with the dual frequency wave than conventional single frequency ones (Figure C). The high efficiency of dual frequency HIFU tissue ablation indicated the possibility of reducing the energy deposition and ablation time for the same heat generation, which is expected to promote the safety and reduce the cost of the HIFU treatment.

HIFU-1

TissueAblation_1

TissueAblation_2

Tissue ablation using dual frequency HIFU (in collaboration with Dr. Weili Lin at UNC, Chapel Hill)

References:

Ma, J., S. Guo, D. Wu, X. Geng, X. Jiang, “Design, fabrication, and characterization of a single-aperture 1.5-MHz/3-MHz dual-frequency HIFU transducer“, Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, 60(7) (2013).
Guo, S., Y. Jing, X. Jiang, “Temperature rise in tissue ablation using multi-frequency ultrasound“, Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, 60(8) (2013).
Guo, S., X.N. Jiang, and W. Lin, “Tissue Ablation Using Multi-frequency Focused Ultrasound”, IEEE Ultrasonic Symposiums, Orlando, October, 2011.