  Nowadays, more and more surgical interventions are carried out in Minimally
Invasive Surgery, to make the post-operative constraints less painful for the
patient. Actually, new surgical tools or medical products are designed after
informal discussions between surgeons and designers. The user requirements
documents are the main document used by the mechanical designers to design and
improve the product. Medical terms, often used by surgeons and employed to
explain their needs, don't allow for an instantaneous understanding by
designers. Unfortunately, this relation causes a dysfunction in the definition
cycle of the product. Our aim is to work on the design process, its assistance
thanks to methods and tools and on its organisation for better understandings
and more complementarities between surgeons and designers. We propose on this
article a design method already tested in the informatics domain: User Centred
Design which takes the user into account more effectively in the process
design. We already propose a scenario oriented design method centred on the
user and represented as a scenario (Scenario-Based Design). We start in this
article by clarifying these concepts before detailing their implementation for
the design of a new surgical tool.
