弧形阵列换能器聚焦特性研究
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摘要
设计一种新型多阵元聚焦换能器,通过对27片自聚焦的圆弧施加延时信号,实现声束的聚焦和偏转,该换能器由27个宽度1.5 mm、曲率半径45 mm、张角60°的弧形阵元线性排列构成,工作频率为350 kHz。用Rayleigh积分对该换能器的声场进行理论推导,并仿真计算自然聚焦和相控聚焦0,10,20 mm状态下的声场分布。实验测量结果表明在-12～12 mm的偏转范围内与仿真基本一致,主瓣声压级降低至-3 dB、-6 dB时,各相控偏转位移对应主瓣宽度与仿真基本吻合,而大于该偏转范围时,主瓣宽度比理论值更大,说明此换能器具有较大的偏转范围与良好的相控聚焦性能,最后讨论由相幅一致性而引入的误差。
A novel multi-element focusing transducer was designed. The acoustic beam which can focus and deflect was achieved by applying a delay signal to 27 self-focusing arcs. The transducer consists of 27 linear array elements with a width of 1.5 mm, a radius of curvature of 45 mm, and an aperture angle of 60 degrees.The operating frequency is 350 kHz. The field of the transducer was theoretically deduced by using Rayleigh integral, and the field distribution under natural focusing and phase-controlled focus at 0, 10, and 20 mm was simulated and calculated. The experimental measurement results show that the simulation is basically consistent with the experiment within the deflection range of-12 mm to 12 mm. When the pressure of the main lobe is reduced by-3 dB and-6 dB, the main lobe width is basically consistent with the simulation in different phased deflection displacements. However, above this deflection range, the main lobe width is greater than the theoretical value. This shows that this transducer has a larger deflection range and good phase focusing performance. Finally, the errors introduced by the consistency of the phases are discussed.
A novel multi-element focusing transducer was designed. The acoustic beam which can focus and deflect was achieved by applying a delay signal to 27 self-focusing arcs. The transducer consists of 27 linear array elements with a width of 1.5 mm, a radius of curvature of 45 mm, and an aperture angle of 60 degrees.The operating frequency is 350 kHz. The field of the transducer was theoretically deduced by using Rayleigh integral, and the field distribution under natural focusing and phase-controlled focus at 0, 10, and 20 mm was simulated and calculated. The experimental measurement results show that the simulation is basically consistent with the experiment within the deflection range of-12 mm to 12 mm. When the pressure of the main lobe is reduced by-3 dB and-6 dB, the main lobe width is basically consistent with the simulation in different phased deflection displacements. However, above this deflection range, the main lobe width is greater than the theoretical value. This shows that this transducer has a larger deflection range and good phase focusing performance. Finally, the errors introduced by the consistency of the phases are discussed.
引文
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[11]CHRIS A,JAMES R M,LU Z N,et al.Excitation of leaky lamb waves in cranial bone using a phased array transducer in a concave therapeutic configuration[J].J Acoust Soc Am,2017,141(5):3918-3918.
[12]单宝华,李冬生,郭佳,等.双层界面下非近轴近似多元高斯模型的相控阵声场模拟[J].声学学报,2017,42(4):457-464.
[13]EUNA C,YONGRAE R.Optimal design of a concave annular high intensity focused ultrasound transducer for medical treatment[J].Sensors and Actuators A,2017(263):91-101.
[14]ROBERT T H,VESNA Z,THUC N N,et al.Annular phasedarray high-intensity focused ultrasound device for imageguided therapy of uterine fibroids[J].IEEE Trans Ultrason Ferroelectr Freq Control,2006,52(2):335-348.
[15]邓鹰飞,刘桂雄,唐文明.FPGA超声相控阵高压发射精确延时设计[J].中国测试,2015,41(5):83-86.
[2]崔建国,韦云隆,王洪.超声治疗学在生物医学工程中的应用[J].重庆工学院学报(自然科学版),2007,21(5):111-114.
[3]FENG W,WANG Z B,CHEN W Z,et al.Extracorporeal high intensity focused ultrasound ablation in the treatment of patients with large hepatocellular carcinoma[J].Ann Surg Oncol,2004,11(12):1061-1069.
[4]张志刚.超声技术在临床治疗中的应用[J].医疗设备信息,2006,21(4):61-67.
[5]FENG W,WANG Z B,CHEN W Z,et al.Advanced hepatocellular carcinoma:treatment with high-intensity focused ultrasound ablation combined with transcatheter arterial embolization[J].Radiology,2005,26(2):117-120.
[6]FAN T B,L IU Z B,CHEN T,et al.A modeling approach to predict acoustic nonlinear field generated by a transmitter with an aluminum lens[J].Medical Physics,2011,38(9):5033-5039.
[7]NICHOLAS E,AKI P,JUNHO S,et al.The utility of sparse2D fully electronically steerable focused ultrasound phased arrays for thermal surgery:a simulation study[J].Phys Med Biol,2001(56):4913-4932.
[8]邹诚,蔡栋,孙振国,等.锯齿形超声相控阵声场特性[J].清华大学学报(自然科学版),2017,57(6):604-608.
[9]章东,桂杰,王晓玲,等.等高度聚焦算法的超声相控阵检测技术[J].电子测量与仪器学报,2018,32(2):42-47.
[10]刘宸,孙宏祥,袁寿其,等.基于热声相控阵列的声聚焦效应[J].物理学报,2017,55(15):154302.
[11]CHRIS A,JAMES R M,LU Z N,et al.Excitation of leaky lamb waves in cranial bone using a phased array transducer in a concave therapeutic configuration[J].J Acoust Soc Am,2017,141(5):3918-3918.
[12]单宝华,李冬生,郭佳,等.双层界面下非近轴近似多元高斯模型的相控阵声场模拟[J].声学学报,2017,42(4):457-464.
[13]EUNA C,YONGRAE R.Optimal design of a concave annular high intensity focused ultrasound transducer for medical treatment[J].Sensors and Actuators A,2017(263):91-101.
[14]ROBERT T H,VESNA Z,THUC N N,et al.Annular phasedarray high-intensity focused ultrasound device for imageguided therapy of uterine fibroids[J].IEEE Trans Ultrason Ferroelectr Freq Control,2006,52(2):335-348.
[15]邓鹰飞,刘桂雄,唐文明.FPGA超声相控阵高压发射精确延时设计[J].中国测试,2015,41(5):83-86.