Smith N, Sankin G N, Simmons W N, Nanke R, Fehre J, Zhong P
Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA.
Rev Sci Instrum. 2012 Jan;83(1):014301. doi: 10.1063/1.3678638.
The performance of a newly developed light spot hydrophone (LSHD) in lithotripter field characterization was compared to that of the fiber optic probe hydrophone (FOPH). Pressure waveforms produced by a stable electromagnetic shock wave source were measured by the LSHD and FOPH under identical experimental conditions. In the low energy regime, focus and field acoustic parameters matched well between the two hydrophones. At clinically relevant high energy settings for shock wave lithotripsy, the measured leading compressive pressure waveforms matched closely with each other. However, the LSHD recorded slightly larger |P_| (p < 0.05) and secondary peak compressive pressures (p < 0.01) than the FOPH, leading to about 20% increase in total acoustic pulse energy calculated in a 6 mm radius around the focus (p = 0.06). Tensile pulse durations deviated ~5% (p < 0.01) due to tensile wave shortening from cavitation activity using the LSHD. Intermittent compression spikes and laser light reflection artifacts have been correlated to bubble activity based on simultaneous high-speed imaging analysis. Altogether, both hydrophones are adequate for lithotripter field characterization as specified by the international standard IEC 61846.
将新开发的光点水听器（LSHD）在碎石机场表征中的性能与光纤探头水听器（FOPH）的性能进行了比较。在相同的实验条件下，用LSHD和FOPH测量了由稳定的电磁冲击波源产生的压力波形。在低能量状态下，两种水听器的焦点和声场声学参数匹配良好。在冲击波碎石术的临床相关高能量设置下，测得的领先压缩压力波形彼此紧密匹配。然而，LSHD记录的|P_|略大（p < 0.05），二次峰值压缩压力比FOPH大（p < 0.01），导致在焦点周围6 mm半径内计算的总声脉冲能量增加约20%（p = 0.06）。由于使用LSHD时空化活动导致拉伸波缩短，拉伸脉冲持续时间偏差约5%（p < 0.01）。基于同步高速成像分析，间歇性压缩尖峰和激光反射伪像已与气泡活动相关联。总之，根据国际标准IEC 61846的规定，两种水听器都适用于碎石机场表征。
