Specification and Verification of Timing Properties in Interoperable Medical Systems

Abstract

To support the dynamic composition of various devices/apps into a medicalsystem at point-of-care, a set of communication patterns to describe thecommunication needs of devices has been proposed. To address timingrequirements, each pattern breaks common timing properties into finer ones thatcan be enforced locally by the components. Common timing requirements for theunderlying communication substrate are derived from these local properties. Thelocal properties of devices are assured by the vendors at the development time.Although organizations procure devices that are compatible in terms of theirlocal properties and middleware, they may not operate as desired. The latencyof the organization network interacts with the local properties of devices. Tovalidate the interaction among the timing properties of components and thenetwork, we formally specify such systems in Timed Rebeca. We use modelchecking to verify the derived timing requirements of the communicationsubstrate in terms of the network and device models. We provide a set oftemplates as a guideline to specify medical systems in terms of the formalmodel of patterns. A composite medical system using several devices is subjectto state-space explosion. We extend the reduction technique of Timed Rebecabased on the static properties of patterns. We prove that our reduction issound and show the applicability of our approach in reducing the state space bymodeling two clinical scenarios made of several instances of patterns