Hydra middleware for developing pervasive systems: a case study in the eHealth domain

In this paper we present from a developer's point of view lessons learned from building an ambient e-health system using Hydra middleware. Hydra provides a middleware framework that facilitates developers to build efficiently scalable, embedded systems while offering web service interfaces for controlling any type of physical device. It comprises a set of sophisticated components taking care of security, device and service discovery using an overlay P2P communication network. We describe in detail how we applied Hydra middleware for an e-health scenario aimed at supporting the routine, medical care of patients at home. Such a scenario illustrates the complexity of a pervasive environment that Hydra aims to solve. We elaborate the process of applying Hydra for building a pervasive environment, the problems we faced, and what we learned for future research.