Dual-Frequency Intravascular Sonothrombolysis: An In Vitro Study.
Dual-Frequency Intravascular Sonothrombolysis: An In Vitro Study.
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DOI：
10.1109/tuffc.2021.3103409
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发表时间：
2021-12
期刊：
影响因子：
--
通讯作者：
Jiang X
中科院分区：
文献类型：
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作者：
Wu H;Goel LD;Kim H;Zhang B;Kim J;Dayton PA;Xu Z;Jiang X
血栓闭塞性疾病是全世界死亡的主要原因之一。在临床前和临床研究中，安全有效的溶栓研究一直在积极进行。最近，据报道，使用造影剂（微泡）的双频经皮超声溶栓在触发声空化方面更有效，从而导致更高的溶栓率。因此，由于小型血管内超声换能器通常具有有限的功率输出以充分利用空化效应，因此人们越来越关注应用双频技术以更显着地提高血管内超声溶栓的效率。在这项工作中，我们通过开发一种新的宽带血管内换能器并在体外测试双频声溶栓，证明了这种功效的增强。设计、制造并表征了中心频率为 750 kHz、占地面积为 1.4 mm 的宽带血管内换能器。测得-6dB分数带宽为68.1%，在80Vpp驱动电压下峰值负压为1.5MPa。通过将一个频率分量保持在750kHz，第二个频率分量从450kHz到650kHz以50kHz的间隔被选择。采用流动模型进行体外声溶栓试验，结果表明，微泡介导的双频（750 kHz + 500 kHz）声溶栓的裂解率比单频治疗高85%，并且双频声溶栓的裂解率随着两个频率分量之间的差异而增加。这些发现表明，与传统的单频激励相比，双频激励技术可以更有效地进行血管内超声溶栓。
Thrombo-occlusive disease is one of the leading causes of death worldwide. There has been active research on safe and effective thrombolysis in pre-clinical and clinical studies. Recently, the dual-frequency transcutaneous sonothrombolysis with contrast agents (microbubbles) has been reported to be more efficient in trigging the acoustic cavitation which leads to a higher lysis rate. Therefore, there is increasing interest in applying dual-frequency technique for more significant effiacy improvement in intravascular sonothrombolysis since a miniaturized intravascular ultrasound transducer typically has a limited power output to fully harness cavitation effects. In this work, we demonstrated this efficacy enhancement by developing a new broadband intravascular transducer and testing dual-frequency sonothromblysis in vitro. A broadband intravascular transducer with a center frequency of 750 kHz and footprint size of 1.4 mm was designed, fabricated, and characterized. The measured −6 dB fractional bandwidth is 68.1%, and the peak negative pressure is 1.5 MPa under the driving voltage of 80 Vpp. By keeping one frequency component at 750 kHz, the second frequency component was selected from 450 kHz to 650 kHz with an interval of 50 kHz. The in-vitro sonothrombolysis tests were conducted with a flow model and the results indicated that the microbubble-mediated, dual-frequency (750 kHz + 500 kHz) sonothrombolysis yields an 85% higher lysis rate compared with the single-frequency treatment, and the lysis rate of dual-frequency sonothrombolysis increases with the difference between the two frequency components. These findings suggest a dual-frequency excitation technique for more efficient intravascular sonothrombolysis than conventional single-frequency excitation.