Development of laparoscopic instruments.

Laparoscopy has important consequences for the functioning of the surgeon, affecting both his/her perception and manipulation capabilities. To be able to judge the perception and manipulation aspects of laparoscopic instruments, a thorough insight into the functioning of the laparoscopic surgeon is needed, and a realistic model of the operation process should be a starting point for every new design. In addition, it is efficient to use observational methods to gain insight into the most important limitations encountered in clinical practice and into the effect of an alternative design. To achieve simplification of the laparoscopic procedure, innovative and unconventional solutions are needed. Thus, the design strategy for laparoscopic instruments is important. Passive and active design strategies, and force- and motion-directed design concepts are reviewed, and their characteristics are compared in view of minimally invasive application. Three design examples are presented and the related design strategy is discussed in each case. These examples are: a laparoscopic grasper with force perception, a passive instrument positioner and a force-controlled robotic system with active constraints. Future trends in the development of laparoscopic instruments are also discussed.