Integrating Regulatory Planning and Metrology into Open-Source Medical Device Research: A Proposed Practice-Informed Framework from the A4IM Low-Field MRI Project

Open-source medical device research can accelerate technical progress, yet later adopters may need to reconstruct how each artefact relates to a system configuration, intended-use hypothesis, and evidence need. We derived a proposed regulatory-planning and metrology framework through a targeted multidisciplinary review, best-fit framework synthesis, and retrospective application to the A4IM low-field magnetic resonance imaging project. Binding requirements under Regulation (EU) 2017/745 were distinguished from guidance, voluntary standards, and research literature. The framework contains seven principles, eight functions, one canonical information model, and four reusable records. An analytical coverage audit mapped 42 source-derived relationship statements to the 8 functions; all were represented, while 5 overlaps were merged and 3 candidate relationships were split to preserve distinct responsibilities. Two public A4IM examples illustrate, but do not validate, the framework. For a 200 mm-diameter spherical volume, the magnet example distinguishes simulated design inhomogeneity (408 ppm), the as-built state (34,143 ppm), and the state after three shimming iterations (1602 ppm), with mean B0 48.47 mT at 24.7 °C. The acquisition example exposes which software and dataset identifiers are publicly recoverable and which remain unreported. The framework is intended to make configuration, risk, metrological evidence, provenance, and later adoption decisions traversable without treating research records as conformity evidence. External validation, implementation burden, time-to-market effects, and transferability remain prospective hypotheses.