The demographic trend in Germany predicts a shift of the age pyramid for the next forty years with an increasing proportion of elderly people who live alone at home. This paper proposes the architecture of an adaptive, humancentered assistance system as a solution for the inherent social changes. This cognitive system determines the actual situation of the user with the help of probabilistic procedures for the evaluation of multiple medical and other physical parameters
like heart rate, blood pressure or the position of the user in order to react in emergency situations appropriately. A straightforward ontology explains the thoughts behind the architecture and demonstrates the semantic integration of an
abstracted emergency detection. Finally the publication recapitulates that human-centered assistance systems which combine ambient assisted technologies facilitate the daily life of elderly people in the future.