This project aims to achieve key technology, infrastructure, and regulatory science advances for next generation medical systems based on the concept of medical application platforms (MAPs). A MAP is a safety/security-critical real-time computing platform for: (a) integrating heterogeneous devices and medical IT systems, (b) hosting application programs ("apps") that provide medical utility through the ability to both acquire information and update/control integrated devices, IT systems, and displays. The project will develop formal architectural and behavioral specification languages for defining MAPs, with a focus on techniques that enable compositional reasoning about MAP component interoperability and safety. These formal languages will include an extensible property language to enable the specification of real-time, quality-of-service, and attributes specific to medical contexts that can be leveraged by code generation, testing, and verification tools. The project will work closely with a synergistic team of clinicians, device industry partners, regulators, and medical device interoperability and safety standard organizations to develop an open source MAP innovation platform to enable key stakeholders within the nation's health care ecosphere to identify, prototype, and evaluate solutions to key technology and regulatory challenges that must be overcome to develop a commodity market of regulated MAP components. Because MAPs provide pre-built certified infrastructure and building blocks for rapidly developing multi-device medical applications, this research has the potential to usher in a new paradigm of medical system that significantly increases the pace of innovation, lowers development costs, enables new functionality by aggregating multiple devices into a system of systems, and achieves greater system safety.