The integration of information technologies into medical systems has led to an increase in digitalization, which results in enormous possibilities, but also challenges in system development. The ever-growing complexity of modern medical devices (MD) requires a system-based development, which must be supported by Model-Based Systems Engineering (MBSE) approaches. Indeed, risk management (RM) and safety analysis must begin in the early development phases to ensure MD's dependability and facilitate the regulatory process. This paper proposes a metamodel that describes the safety and RM concepts related to the medical domain. This metamodel enables safety and quality experts to analyze MD and demonstrate compliance with the recommendations of ISO 14971. We have validated the proposed metamodel using the academic example of a wearable system designed for real-time EEG-based subject monitoring.