Etienne J, Filipczyński L, Kujawska T, Zienkiewicz B
Department of Ultrasound, Polish Academy of Sciences, Warsaw, Poland.
Ultrasound Med Biol. 1997;23(5):747-54. doi: 10.1016/s0301-5629(97)00006-9.
An electromagnetic hydrophone has been designed and tested to determine its ability to measure shock wave pulses similar to those produced by lithotripter machines. The principle of operation of the hydrophone, its design and performance are described. The hydrophone was exposed to 4000 shots and peak compressional pressures on the order of 30 MPa without any deleterious effects of its performance and operation. The hydrophone can be calibrated directly by measurement of the magnetic field of the permanent magnet and voltage induced in the electrical conductor. While the spatial resolution of the electromagnetic hydrophone is limited by the length of the vibrating conductor and was determined to be 5 mm, it can be improved. The overall bandwidth of the hydrophone, including its integral preamplifier, had to be limited to 17 MHz; however, the hydrophone appears to reproduce correctly the general shape of the propagating shock wave pulse. The influence of the hydrophone's bandwidth on the measured pulse shape and its amplitude is analysed, and it is shown that it affects rise time and peak compressional pressure. However, no deteriorating influence was observed in reproduction of peak rarefactional pressure.
设计并测试了一种电磁水听器，以确定其测量类似于碎石机产生的冲击波脉冲的能力。描述了该水听器的工作原理、设计和性能。该水听器经受了4000次冲击，峰值压缩压力约为30MPa，其性能和运行未受到任何有害影响。该水听器可通过测量永久磁铁的磁场和电导体中感应的电压直接进行校准。虽然电磁水听器的空间分辨率受振动导体长度的限制，确定为5mm，但可以改进。该水听器包括其内置前置放大器的总带宽必须限制在17MHz；然而，该水听器似乎能正确再现传播的冲击波脉冲的大致形状。分析了水听器带宽对测量脉冲形状及其幅度的影响，结果表明它会影响上升时间和峰值压缩压力。然而，在峰值稀疏压力的再现中未观察到恶化影响。
