ABSTRACT
Abstract. When describing criteria for the acceptable safety of systems, it is common practice for the regulator to provide safety requirements that should be satisfied by the system. These requirements are typically described precisely but in natural language and it is often unclear how the regulator can be assured that the given requirements are satisfied. This chapter applies a rigorous refinement process to demonstrate that a precise requirement is satisfied by the specification of a given medical device. It focuses on a particular class of requirements that relate to the user interface of the device. For user interface requirements,
From Approach
refinement is made more complex by the fact that systems can use different interaction technologies that have very different characteristics. The described refinement process recognises the variety of interaction technologies and models them as an interface hierarchy.
