Purpose

To measure the time to fragment removal and number of chatter events using various combinations of micropulse on times and off times (measured in milliseconds) of longitudinal ultrasound (US) using a venturi-based phacoemulsification system.

Setting

John A. Moran Eye Center, University of Utah, Salt Lake City, USA.

Design

Experimental study.

Methods

Pig lenses were hardened with formalin and cut into 2.0 mm cubes. The time to fragment removal (efficiency) and frequency of fragments bouncing off the tip (chatter) were measured with the venturi-based system. Micropulse longitudinal US was tested. Parameters were combinations of 5, 6, and 7 milliseconds on, with 5, 6, and 7 milliseconds off. Twenty runs each of 9 combinations were completed.

Results

There was a statistically significant difference between on/off duty cycle combinations. The 6 on/7 off group had higher efficiency than the 5 on/6 off and 7 on/7 off groups. Six on/5 off was more efficient than 5 on/6 off. When data were pooled and on times alone were used, 6 milliseconds on time was more efficient than 5 or 7 milliseconds. No efficiency differences in off times were found. No significant chatter differences were observed.

Conclusions

Using micropulse longitudinal US in venturi vacuum mode, 6 milliseconds on was the most efficient on time. Five, 6, and 7 milliseconds off times had similar efficiency. These data suggest that the most efficient setting with lowest US energy use is 6 milliseconds on and 7 milliseconds off.

中文翻译：

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文丘里真空模式下微脉冲超声乳化的最佳开启和关闭时间组合

目的

使用基于文丘里超声的超声乳化系统，使用纵向超声（US）的开启和关闭时间（以毫秒为单位）的微脉冲的各种组合来测量碎片去除的时间和颤动事件的数量。

设置

美国盐湖城犹他大学John A.Moran眼科中心。

设计

实验研究。

方法

猪镜片用福尔马林硬化并切成2.0毫米的立方体。用基于文丘里管的系统测量去除碎片的时间（效率）和从尖端反弹（碎片）的碎片的频率。测试了微脉冲纵向US。参数是打开5毫秒，6毫秒和7毫秒，关闭5毫秒，6毫秒和7毫秒的组合。9个组合中的每一个完成20个运行。

结果

开/关占空比组合之间在统计上有显着差异。6 on / 7 off组的效率高于5 on / 6 off和7 on / 7 off组。6开/ 5关比5开/ 6关效率更高。当汇总数据并仅使用打开时间时，打开6毫秒比打开5或7毫秒更有效。没有发现关闭时间的效率差异。没有观察到明显的震颤差异。

结论

在文丘里真空模式下使用微脉冲纵向US，最准时的时间是6毫秒。关闭时间分别为5、6和7毫秒，效率相似。这些数据表明，美国能源消耗最低的最有效设置是开启6毫秒和关闭7毫秒。