Designing new technological products or services for improving health care raises many challenges today, namely improving the innovative care process, bringing health actors to develop new value propositions and reconciling the logic of business and the logic of social economy around health. The health ecosystem is not the only sector in which such an issue emerges. Indeed, the question of the management of an industrial ecosystem arises today in many sectors seeking a renewal of their capabilities for innovation. In such situations, empirical and theoretical studies show the emergence of new actors--innovation intermediaries--who aim to influence the innovation process. Recently, scholars have enriched the description of the diversification of the role of such actors, showing how those actors can take a more active role within the innovation process. Our goal in this paper is to examine the role that Living Labs can play in the health ecosystem as architects of the unknown, i.e., innovation intermediaries acting to improve the innovation capabilities of other stakeholders. Building on both a description of the contemporary stakes of innovating in the health ecosystem and the literature on innovation intermediaries, we examine a case study in the Rhône-Alpes region in France in which we show how structures like Living Labs can act as architects to stimulate innovation and to help new concepts to emerge. This article therefore contributes to deepen the emerging stream of research that studies the concept of Living Labs and enriches our understanding of the activities that innovation intermediaries can undertake within the health ecosystem.