title: Laparoscopic multifunctional instruments: design and testing of initial prototypes.
abstract: BACKGROUND
  Advances in minimally invasive surgical techniques will require new types of instrument end-effectors for smaller, longer, and flexible instruments. These include a new class of multifunctional instruments capable of performing more than 1 task with a single set of working jaws. Furthermore, it is desired that multifunctional instruments be designed to provide improved dexterity compared with that in currently commercially available instruments.
  
  
  METHODS
  Three prototypes of multifunctional laparoscopic surgical instruments are described: (1) a mechanical scissors-grasper, (2) a mechanical scissors-grasperarticulator, and (3) a compliant mechanism scissors-grasper. Methods of baseline analysis, design methods and considerations, and subjective evaluations of interim prototypes are presented.
  
  
  RESULTS
  The 3 prototypes demonstrate promising early results. However, based on subjective evaluation, these prototypes do not perform individual functions as well as basic disposable single-function laparoscopic instruments do.
  
  
  CONCLUSIONS
  The concept of multifunctionality and increased end-effector dexterity is achievable as demonstrated by the prototypes presented. Further work is required to refine, simplify, and improve the multifunctional instruments to a point where they may be useful as surgical tools.
authors.affiliation: Department of Mechanical and Nuclear Engineering, College of Engineering, Penn State University, University Park, Pennsylvania 16802, USA. mxf36@psu.edu
authors.forename: Mary I
authors.initials: MI
authors.lastname: Frecker
authors.forename: Jeremy
authors.initials: J
authors.lastname: Schadler
authors.forename: Randy S
authors.initials: RS
authors.lastname: Haluck
authors.forename: Kristin
authors.initials: K
authors.lastname: Culkar
authors.forename: Ryan
authors.initials: R
authors.lastname: Dziedzic
mesh_terms: D004867:Equipment Design; D020706:Laparoscopes