球形集声器在生物组织中形成的组织损伤

球形集声器可在亚波长焦域内形成高强度声压,在高强度聚焦超声治疗中具有潜在应用前景.本文结合非线性声传播理论及生物传热学理论,研究球形集声器在生物组织中形成的组织损伤.实验中采用430 kHz,内径为240 mm的球形集声器对肝组织作用,结果表明:集声器表面声压为53 kPa时作用2 s,可以形成小于波长尺度的组织损伤.理论计算结果与实验结果符合得较好,并且理论模型可优化球形集声器的开口孔径.研究结果表明,球形集声器可应用于肿瘤的精细超声治疗.

Tissue lesion induced by a spherical cavity transducer

Spherical cavity transducer can generate high acoustic pressure in a narrow focal region at a sub-wavelength level, which suggests a great potential application in high intensity focused ultrasound (HIFU) treatment. In this paper, tissue lesion induced by a spherical cavity transducer is investigated based on the nonlinear acoustics theory and bio-heat transfer theory. A 430 kHz spherical cavity transducer with a diameter of 240 mm is used to generate tissue lesion for liver tissues. The result shows that the tissue lesion with a size less than a wavelength can be formed under the 2 s HIFU exposure at a acoustic pressure of 53 kPa. The numerical simulations coincide well with the experimental measurements, and the optimization of the design of the spherical cavity transducer is also discussed. This work demonstrates that the spherical cavity transducer can be used in the accurate HIFU tumor treatment.