Context: Recently developed concepts for higher efficacy ESWL with low-pressure wide focus systems resulting in finer fragmentation of the calculi. Objective: To compare two different electromagnetic shock wave sources (low-pressure wide focus (XL) versus high-pressure small focus (SL)) by sound-field measurements and in-vitro fragmentation. Evidence acquisition: The CS-2012A XX-ES lithotripter (self-focusing electromagnetic shock-wave generator with concave spherical curved electrical coil; Xinin Lithotripter = XL) was compared to the Siemens Lithoskop (= SL) (electromagnetic generator with a flat electric coil with an acoustical lens). Different sound-field measurements were performed using a fiber-optic hydrophone. Measurements at three different power settings (XL: 8.0kV, 9.3kV and 10.3kV; SL: Level 1, 5 and 8). 10 ATS-stones and 15 BegoStones (9.3 kV, Level 3) with a frequency of 90/minute (SL) and 20/minute (XL). Number of impulses to the first crack and for complete stone comminution (residual fragments <2mm) were documented. Results: The median number of shock waves for the first crack in ATS-stones with the XL was 12 (10-14), with the SL 7 (6-9). Complete disintegration was accomplished after 815 (782-824) shock waves with XL, 702 (688-712) with SL. The difference was not statistically significant. The median number of shock waves to produce the first crack in BegoStones was 524 (504-542) with XL and only 151 (137-161) with SL. Numbers of shock waves for complete disintegration did not differ significantly (XL:2518 vs SL:2287). Using a wide focus with low pressure shows more homogeneous disintegration. Conclusion: Two stone models showed significant differences regarding form and time of the initial fragmentation. Impulses for stone comminution did not differ significantly. The advantages of a low-pressure wide focus-system include minimal trauma and a homogeneous fragment size but is more time consuming. High-pressure small focus systems are clinically effective.

中文翻译：

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两种电磁冲击波发生器的体外比较：低压宽焦点与高压小焦点——对初始结石碎裂和最终结石粉碎的影响

背景：最近开发的更高效率 ESWL 概念与低压广焦系统导致更精细的结石碎裂。目的：通过声场测量和体外破碎比较两种不同的电磁冲击波源（低压宽焦点 (XL) 与高压小焦点 (SL)）。证据获取：将 CS-2012A XX-ES 碎石机（带有凹球形弯曲电线圈的自聚焦电磁冲击波发生器；Xinin Lithotripter = XL）与 Siemens Lithoskop (= SL)（带有扁平电线圈的电磁发生器）进行了比较带有声学透镜）。使用光纤水听器进行不同的声场测量。在三种不同的功率设置下进行测量（XL：8.0kV、9.3kV 和 10.3kV；SL：1、5 和 8 级）。10 个 ATS-stones 和 15 个 BegoStones（9.3 kV，3 级），频率为 90/分钟 (SL) 和 20/分钟 (XL)。记录第一次破裂和完全粉碎结石（残留碎片 <2 毫米）的脉冲数。结果：ATS 结石第一次裂纹的冲击波数中位数为 12 (10-14)，SL 为 7 (6-9)。在 815 (782-824) 次 XL 冲击波和 702 (688-712) 次 SL 冲击波后完成完全崩解。差异无统计学意义。在 BegoStones 中产生第一次裂纹的冲击波的中位数是 524 (504-542) 与 XL 和只有 151 (137-161) 与 SL。完全崩解的冲击波数量没有显着差异（XL：2518 vs SL：2287）。使用低压宽焦点显示更均匀的崩解。结论：两种石头模型在初始碎裂的形式和时间方面显示出显着差异。结石粉碎的冲动没有显着差异。低压广焦系统的优点包括创伤最小和碎片大小均匀，但更耗时。高压小焦点系统在临床上是有效的。