This study characterizes the temporal and spectral property of the mechanical impulsive waves produced by a clinical ballistic shock wave therapy device. The impulsive waves were generated by a projectile impacting a metallic shock wave transmitter, and were measured using a laser vibrometer that detects vibrations on the front surface of the shock wave transmitter. The shock wave transmitter considered in the measurement has a circular flat surface tip with a diameter of 15 mm. The results showed that the measured impulsive wave was resonated at 93.4 kHz and modulated with a relatively low frequency of 3.7 kHz to form a heavily damped pulse wave lasting for longer than 2 ms. Multiple impulsive waves produced at high output settings, were observed for the first time, and their clinical implication needs to be elucidated in the future study. Despite measurements made on the cavitation free air born impulsive waves, the study was justified by the experimental clarification that their temporal and spectral properties were characteristically similar to those of the impulsive waves produced in water, more representative to clinical conditions. The present results are expected to deliver critical information for assessing the shock wave dose delivered from a clinical radial extracorporeal shock wave device to patients.

中文翻译：

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临床弹道冲击波治疗装置产生的脉冲波的时间和频谱特性

本研究表征了由临床弹道冲击波治疗设备产生的机械脉冲波的时间和光谱特性。冲击波由弹丸撞击金属冲击波发射器产生，并使用激光测振仪测量冲击波发射器前表面的振动。测量中考虑的冲击波发射器具有直径为 15 mm 的圆形平面尖端。结果表明，测得的脉冲波在 93.4 kHz 谐振并以 3.7 kHz 的相对较低频率调制，形成持续时间超过 2 ms 的重阻尼脉冲波。首次观察到在高输出设置下产生的多个脉冲波，其临床意义需要在未来的研究中阐明。尽管对无空化空气产生的脉冲波进行了测量，但实验澄清证明了该研究是合理的，即它们的时间和光谱特性与水中产生的脉冲波的特征相似，更能代表临床条件。目前的结果有望为评估从临床径向体外冲击波装置传递给患者的冲击波剂量提供关键信息。