This case study traces how a health-tech start-up, "MediVision AI", used the EU regulatory sandbox to validate a high-risk AI system -- a diagnostic imaging aid -- before CE marking.

The Journey: From Concept to CE Marking

Phase 1: MediVision applies to the national sandbox with a plan to test its AI on anonymised imaging data in two hospital sites
Phase 2: NCA approves the sandbox plan; MediVision begins 12 months of supervised testing with patient informed consent
Phase 3: Testing reveals a performance gap in images from patients with certain demographic characteristics; MediVision documents this and retrains the model
Phase 4: Post-retrain testing demonstrates improved performance across groups; Article 9 risk management documentation is updated
Phase 5: MediVision exits the sandbox with a complete Annex IV technical documentation package
Phase 6: Conformity assessment by notified body (required for medical device AI under Annex I); CE mark affixed; registration in EU AI Act database
Outcome: MediVision achieves market entry 8 months faster than competitors who did not use the sandbox pathway