Sankin Georgy N, Fang Zheng, Gu Juanjuan, Jing Yun, Zhong Pei
Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA.
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA.
Front Urol. 2023;3. doi: 10.3389/fruro.2023.1057723. Epub 2023 Mar 13.
All clinical shock wave lithotripters produce an axisymmetric acoustic field without accounting for the anatomic features of the kidney or respiratory motion of the patient. This work presents a steerable and adjustable focusing electrohydraulic (SAFE) shock wave generator design with variable beam size and shape.
90 electrohydraulic transducers are mounted concentrically on a spherical basin with adjustable connection to individual transducers. Each transducer consists of 45 3D-printed titanium microelectrodes embedded in epoxy with a tip diameter of 0.3 mm. All the transducers are arranged in 5 concentric rings and sub-divided into 6 sectors.
By changing the connections of individual transducers, the focused pressure field produced by the transducer array can be either axisymmetric with a -6 dB focal width of 14.8 mm in diameter, or non-axisymmetric with a long axis of 22.7 mm and a short axis of 15.1 mm. The elongated beam produces a peak positive pressure of 33.7±4.1 MPa and comminution efficiency of 42.2±3.5%, compared to 36.2±0.7 MPa and 28.6±6.1% for axisymmetric beam after 150 pulses at 20 kV.
We have demonstrated that the SAFE shock wave generator can produce an elongated non-axisymmetric pressure field with higher stone comminution efficiency. The SAFE shock wave generator may provide a flexible and versatile design to achieve accurate, stable, and safe lithotripsy for kidney stone treatment.
所有临床冲击波碎石机均产生轴对称声场，未考虑肾脏的解剖特征或患者的呼吸运动。本文介绍了一种具有可变束大小和形状的可控可调聚焦电液压（SAFE）冲击波发生器设计。
90个电液压换能器同心安装在一个球形盆上，与各个换能器的连接可调。每个换能器由45个3D打印的钛微电极组成，这些微电极嵌入环氧树脂中，尖端直径为0.3毫米。所有换能器排列成5个同心环，并细分为6个扇区。
通过改变各个换能器的连接，换能器阵列产生的聚焦压力场可以是轴对称的，-6 dB焦距直径为14.8毫米，也可以是非轴对称的，长轴为22.7毫米，短轴为15.1毫米。与20 kV下150个脉冲后轴对称束的36.2±0.7 MPa和28.6±6.1%相比，细长束产生的峰值正压力为33.7±4.1 MPa，粉碎效率为42.2±3.5%。
我们已经证明，SAFE冲击波发生器可以产生具有更高结石粉碎效率的细长非轴对称压力场。SAFE冲击波发生器可能提供一种灵活通用的设计，以实现肾结石治疗的精确、稳定和安全的碎石术。
