Mechanical Design of a Minimally Invasive Surgery Trainer Using the Manipulability as Measure of Optimization

The trainers based in virtual reality have come up with an enormous interest in the field of Minimally Invasive Surgery. They provide a non degradable realistic training environment where apprentices are able to gain skills without limitations or risks. They may learn and try as much as desired, with no additional cost after the installation of the system. In this paper, we describe our contribution to a multidisciplinary project for the development of a Minimally Invasive Surgery Trainer. The aim of our work has been to optimize the mechanical relative positioning of haptic devices into the system platform. With this purpose we have defined a measure of how the operation workspace fits within the volume where haptic device provides its best manipulability. Then we have defined another measure that takes into account the frequency with which each zone of the operation workspace is visited during the simulation session. Using these tools, a prototype of mechanical platform involving two haptic devices has been designed and built. The placement of each device has been optimized for each zone of the operation workspace in function of its role, manipulability and frequency of use.