Wireless sensor nodes are used to monitor patient vital signs in a medical application. To ensure proper patient care is provided, real-time patient data must be managed correctly in the context of relevant patient information and medical knowledge. The Data Management System (DMS) is an agent-based architecture that aims to provide flexible, effective data management within a Wireless Patient Sensor Network (WPSN). The DMS is built primarily on the sophisticated JADE agent platform. JADE runs on resource-rich platforms such as servers, PCs, PDAs and high-end mobile phones. The lightweight Agilla agent platform can run on resource constrained sensor nodes. An integrated mobile agent based architecture combining Jade and Agilla is presented. This makes best use of the more sophisticated agent platform for high-level functionality and the lighter agent middleware for low-level sensor data collection. The resulting system is a unified agent architecture that runs on heterogeneous platfor...