摘要
目的:聚焦超声治疗妇科浅表组织疾病中存在聚焦换能器和定位探头同时放置的问题,在实际的治疗头设计中必须考虑放置B超探头对聚焦声场的影响,本文涉及一种开口柱面换能器聚焦超声声场的数值计算与仿真,通过计算得出声场的三维空间分布,同时研究柱面自聚焦换能器中不同开口形状、位置、面积大小对声场的影响,以指导开口换能器的实际设计。方法:本文通过建立三维直角坐标系,应用Rayleigh积分得出柱面换能器聚焦区域内每一点的声强表达式,运用C语言和matlab采用变步长辛卜生二重积分的方法对开口柱面聚焦超声换能器的声场进行了数值计算和仿真,得出声场的三维分布。结果:对开口的不同形状、大小、位置的声场分布仿真结果表明:不同开口形状都会使聚焦区域声压幅值下降,开口半径增大,声压表现为下降的趋势,Z轴向的声压在换能器的边缘较大,中间小。随着开口中心位置距原点的距离越大,Z轴向的声压分布越不均匀,而对聚焦位置影响不大。结论:通过不同开口参数对声场三维分布影响可以看出:柱面超声换能器的开口形状、位置、面积对聚焦区域的声压均有明显影响。与给定的条件相比,选择位置居中、面积较小、的换能器,能使聚焦性能得到提高,而换能器的开口形状对聚焦效果影响不大。
Objective： Focused ultrasound treatment of superficial tissue disease,gynecological there focused transducer placed at the same time and location of the probe problems in the actual design of the treatment must be considered in the first place the B-probe the impact of the sound field of focus,This relates to a cylindrical opening focused ultrasound transducer sound field of numerical calculation and simulation,calculated by three-dimensional sound field distribution,while the self-focusing of cylindrical transducer in different opening shapes,location,size of the sound field impact,to guide the opening of the actual transducer design.Methods： In this paper,three-dimensional Cartesian coordinate system,the application of variable-step method of Simpson double integral focused ultrasound on the open cylinder transducer sound field for a numerical calculation and simulation, draw three-dimensional sound field distribution.Results： Openings of different shapes,sizes,location of the sound field distribution simulation results show that： different shape of the opening pressure will cause the amplitude of the focus area decreased, opening the radius increases,the pressure showed a downward trend,Z axis of the sound pressure in the exchange can control the edge of the large middle small.With the open center of the greater distance from the origin,Z axis of the sound pressure distribution more uneven,but has little effect on the focus position.Conclusions： We can see from the effects on the distribution of the three-dimensional sound field of different parameters： cylindrical ultrasound transducer opening shape,location, size of the focus areas of sound pressure are significantly affected.Compared with the given conditions,selected centrally located, smaller,transducers,focusing performance can be improved,and the opening shape of the transducer little effect on the focus.
出处
《中国医学物理学杂志》
CSCD
2011年第5期2890-2894,共5页
Chinese Journal of Medical Physics
基金
国家自然科学基金(No.30772072)
关键词
柱面换能器
声场
超声聚焦
cylinder transducer
acoustic field
focused ultrasound
