Design and Implementation of an Event-Driven Architecture for Medical Software

Software has become the main value driver of medical devices. Improvements of already developed medical devices are often only achieved through the further development of software components. These are often usability enhancements and the ability to connect with other medical devices or information systems. To ensure the integrity of patients’ and operators’ health, the development of medical software is regulated by law. However, there are two opposing requirements here. On one hand, the medical software must be continually developed, for example to update an algorithm or to improve the usability of the user-interface. On the other hand, development must comply with legal requirements, which may be cumbersome and requires a lot of documentation and testing.

The architecture of a medical software must be easily extensible and modifiable to meet both requirements. This thesis shows how an extensible and modifiable system can be ensured using an Event-Driven Architecture. Using a medical application scenario an event-driven architecture is designed and implemented. The system is composed of individual applications which are loosely coupled and communicate only via the exchange of events. It is demonstrated, how this structure allows the extension of the architecture by adding applications during operation. Different tools and technologies for the implementation of the event-driven approach are compared and selected. Moreover, solution strategies are presented, which address the challenges when implementing the event-driven architecture.

Such architectures also simplify automated integration tests. For this purpose, a domain specific language is developed which allows to simulate and test the interaction between different sub-applications of the system. The test cases created can be easily integrated into the build process and thus shorten the release cycles of the application significantly. All presented advantages of the designed event-driven architecture optimize the development of medical software for compliance with the IEC 62304 standard and a successful declaration of conformity. Thus, the time-to-market for new product features of a medical device will be significantly reduced.