During the first COVID19 wave, the trust of Greater Paris academic hospitals (Assistance Publique - Hôpitaux de Paris) faced an unprecedented situation: a significant number of medical devices were used in extraordinary quantities and international supply chains were defective or interrupted. To overcome the risk of shortage, a team of health professionals and engineers settled a central emergency 3D-printing platform. This book tells the story of this initiative, reports its results, and proposes general guidelines for the integration of additive manufacturing in hospitals. 3D-printing has transformed our approach to the conception and production of the tools we use to treat patients. For the first time in modern history, professional production machines can be located within health institutions. 3D platforms are extraordinary boosters of innovation, research, education, and valorisation. Based on a particular story, this book investigates the paths leading to innovation in public structures and proposes guidelines for the promotion of interactions between health professionals and engineers.