CAJ | 학술논문

在线性声学条件下,研究了差频相干模式下的双频聚焦声场的空间-时间特性,分析了换能器分割面积、不同频差对声场的影响.通过计算两波在不同初始相位时轴上瞬时声压起伏的周期性变化规律,证明其合成声场是统计平稳和均匀的.结果表明,适当选择分割面积比和频差,双频声场的"损伤声焦域"相对于单频有明显扩大,并在离体牛肝的损伤实验中得到初步验证,为双频高强度聚焦超声(HIFU)换能器的设计及提高治疗效率提供参照.
재선성성학조건하,연구료차빈상간모식하적쌍빈취초성장적공간-시간특성,분석료환능기분할면적、불동빈차대성장적영향.통과계산량파재불동초시상위시축상순시성압기복적주기성변화규률,증명기합성성장시통계평은화균균적.결과표명,괄당선택분할면적비화빈차,쌍빈성장적"손상성초역"상대우단빈유명현확대,병재리체우간적손상실험중득도초보험증,위쌍빈고강도취초초성(HIFU)환능기적설계급제고치료효솔제공삼조.
The spatial and temporal characteristics of dual-frequency focused acoustic field of the differential frequency coherence mode were investigated in this paper under the linear acoustic condition, and the effect of partition area of HIFU transducer and various frequency differences on the dual-frequency HIFU acoustic field were also analyzed. It was proved that the composite sound field was smooth and uniform by calculating the periodic variational regularity of the fluctuation of instantaneous sound pressure generated by two waves at difference initial phases. The result indicates that with the proper choice of partition area proportion and frequency difference, the injury sound focal region of dual-frequency acoustic field is larger than that of a single frequency significantly. That has been preliminarily validated by the ex-vivo experiment of cattle liver ablation. It provides a reference to the design of dual-frequency focused transducer and the enhancement of treatment efficiency.