Abstract
We have designed and implemented a Context-aware ONTOlogical (C-ONTO) schema for pervasive computing environments in hospitals. The schema contains semantics for situation awareness, which has been drawn from sensor-derived information about patients, called local contexts; changes to these contexts, and users involved in, and actions taken as a result of, these context changes. We have modeled and implemented situation awareness in C-ONTO through the transitive relationship between its ontological classes.