单人反套防护套内超声刀安装的效果分析

目的寻找一种满足临床需要的快速有效的超声刀安装方法。方法将20条全新限次超声刀手柄线随机分为两组放置于手术间，各取500例超声刀安装实例，对照组采用双人合作防护套内超声刀的安装法安装（简称双人法），观察组采用单人反套防护套内超声刀的安装法（简称单人法），记录两组数据的安装时间，安装一次通过率，超声刀手柄有效使用率及安装污染率，并将这些数据进行比较。结果与双人法比较，单人法安装花费时间少，为（57±2．6）s；安装一次通过率高达98．8％；手柄有效使用率高达98．2％；二者安装污染率为0，均符合无菌要求。结论单人反套防护套内超声刀安装快速，成功率高，符合手术台上使用的无菌要求，并在一定程度上延长了超声刀的使用寿命。

Contrastive analysis and crashworthiness optimization of two composite thin-walled structures

For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can be completely absorbed or dissipated for the aim of safety. Two composite structures(circumscribed circle structure and inscribed circle structure) were constructed. In addition, comparison and optimization of the crashworthy characteristic of the two structures were carried out based on the method of explicit finite element analysis(FEA) and Kriging surrogate model. According to the result of Kriging surrogate model, conclusions can be safely drawn that the specific energy absorption(SEA) and ratio of specific energy absorption to initial peak force(REAF) of circumscribed circle structure are lager than those of inscribed circle structure under the same design parameters. In other words, circumscribed circle structure has better performances with higher energy-absorbing ability and lower initial peak force. Besides, error analysis was adopted and the result of which indicates that the Kriging surrogate model has high nonlinear fitting precision. What is more, the SEA and REAF optimum values of the two structures have been obtained through analysis, and the crushing results have been illustrated when the two structures reach optimum SEA and REAF.