The nonstop ageing of population in Europe makes the health system maintenance a worrying and complicated task for every government. In this context, telecare systems emerge as a cheap and effective approach. A telecare system helps elderly and care-dependent people to satisfy their needs and special requirements, requiring fewer resources and enabling users to be at their own homes. The purpose of this paper is to define a telecare conceptual system architecture based on ontologies, rules and inference engines, machine learning techniques and data mining procedures. Some open sources are also proposed in order to develop certain modules of this architecture. The approach tries to provide a representation of an entire telecare system, offering customised solutions for users, professional care facilities and service centres.