How to assure correctness and safety of medical software: the hemodialysis machine case study

Medical devices are nowadaysmore and more software dependent, and software malfunctioning can lead to injuries or death for patients. Several standards have been proposed for the development and the validation of medical devices, but they establish general guidelines on the use of common software engineering activities without any indication regarding methods and techniques to assure safety and reliability. This paper takes advantage of the Hemodialysis machine case study to present a formal development process supporting most of the engineering activities required by the standards, and provides rigorous approaches for system validation and verification. The process is based on the Abstract State Machine formal method and its model refinement principle.