New ergonomic design criteria for handles of laparoscopic dissection forceps

Background: The shape of laparoscopic instrument handles can cause physical discomfort. This problem may be ascribed to a lack of standards for instru ment design. In this study, new ergonomic requirements for the design of la paroscopic dissection forceps were created. Three representative handles (a Karl Storz [click-line] scissors handle, an Access Plus scissors handle, a nd an Aesculap cylindrical handle) currently available on the market were e valuated according to the new list of ergonomic criteria. Materials and Methods: The handles were subjectively (questionnaire) and ob jectively (video analyses) tested in order to find out whether the new requ irements are valid for the evaluation and design of instrument handles. Results: The outcome of the subjective and objective tests matched the pred ictions by the new criteria list. New criteria were introduced (neutral wri st excursions), and existing general criteria were specified (e.g., a minim al contact area of 10 mm). Significant differences were found among the thr ee handles. The Storz handle met 8 of the 10 requirements, the Access handl e met 5, and the Aesculap handle met only 4. Conclusions: The new list of ergonomic requirements is a valid tool to dete rmine the ergonomic value of a handle for laparoscopic dissecting tasks. It gains its strength from its specialized character. Significant differences were found among the three tested handles. Cylindrical handles were inferi or to scissors handles.