Abstract. In this paper, three aspects of the use of compliant mechanisms for a new surgical tool, an active cardiac stabilizer, are outlined. First, the interest of compliant mechanisms in the design of the stabilizer is demonstrated with in vivo experimental evaluation of the efficiency of a prototype. We then show that the specific surgical constraints lead to the development of compliant mechanisms, with the design of new original mechanical amplifiers. Finally, the requirements in the design of stabilizers exhibiting a higher level of integration are outlined. Novel architectures and design procedures are actually needed, and we introduce an exploratory study with a proof-of-concept designed using the combination of ant colony optimization and classical pseudo rigid body modeling. Relative errors in the estimation of the displacement do not exceed 5%. The proposed design method constitutes an interesting approach that may be applied more generally to the design of compliant mechanisms.