Cathignol D, Birer A, Nachef S, Chapelon J Y
INSERM U 281, Lyon, France.
Ultrasound Med Biol. 1995;21(3):365-77. doi: 10.1016/0301-5629(94)00115-t.
Shock-wave generators are now currently used for the treatment of renal stones. In all these generators the focal zone is determined by their geometrical parameters. We propose, for the first time, a piezocomposite shock-wave generator with electronic focusing. The system is composed of a two-dimensional array and its electronic hardware. The array is composed of 121 independent piezocomposite transducers arranged in a spherical shell 20 cm in diameter and focused at 190 mm. The electronic hardware includes 121 x 6 kV-impulse generators. The interdelay of each channel can be adjusted between 10 ns to 100 microseconds by steps of 10 ns. The results show: the use of composite material is possible for the generation of high amplitude pressure waves; the pressure-voltage relationship is linear up to a pressure of about 28 x 10(5) Pa at the transducer front face; the material can be used for a long period of time; i.e., after one million shocks, no decrease in sensitivity, no alteration in its electrical behaviour and no time wave form distortion were observed. Electronic focusing is efficient in an ellipsoidal region of about 4 cm in diameter and 6 cm in length. The pressure in the focal zone is about 600 x 10(5) Pa.
冲击波发生器目前用于治疗肾结石。在所有这些发生器中，聚焦区由其几何参数决定。我们首次提出一种具有电子聚焦功能的压电复合冲击波发生器。该系统由二维阵列及其电子硬件组成。该阵列由121个独立的压电复合换能器组成，排列在一个直径20厘米的球壳中，聚焦在190毫米处。电子硬件包括121个6 kV脉冲发生器。每个通道的延迟可以在10纳秒到100微秒之间以10纳秒的步长进行调整。结果表明：使用复合材料可以产生高振幅压力波；在换能器正面，压力与电压的关系在约28×10⁵帕的压力范围内呈线性；该材料可以长期使用；即，在经历一百万次冲击后，未观察到灵敏度下降、电性能改变和时间波形失真。电子聚焦在一个直径约4厘米、长度约6厘米的椭圆形区域内是有效的。聚焦区内的压力约为600×10⁵帕。
