This talk aims at introducing some of the works that are carried out in the Computer-Aided Group of TIMC Laboratory (Technologies for Imaging, Modeling and Cognition), France. The first application concerns plastic and maxillo-facial surgery. A 3D biomechanical model of the human face soft tissues is presented and used to predict the consequences of bone osteotomies. Predictions provided by the model are compared with patients post-operative CT scans. The second application deals with obstetrics and digestive surgery. The robotic devices that are developed at TIMC are presented and discussed for two clinical applications, namely digestive endoscopy and tele-echography.