Furthermore, there is a trend towards technologies that achieve prevention of disease. These technologies have now reached the point where they have become enabling technologies in clinical applications [1]. Substituting traditional sensors by smart textiles for health monitoring has been another hot topic in the last few years [2]. Several research groups and industry have initiated projects in this area, for instance MyHeart (http://www.hitech-projects.com/euprojects/myheart/), an EU FP6 project with Philips Research as one of the major contributors, focusing on vital sign monitoring, and HeartCycle (http://heartcycle.med.auth.gr/), also coordinated by Philips, produced a key result in the provision of closed-loop disease management.

In the industry, the Continua Health Alliance [3], which started in 2006 to enable an interoperable personal telehealth ecosystem, has become a major force in the personal telehealth domain, and over a dozen interoperable products have already been certified. Continua has also made great progress in defining interoperability for the LANand WANinterfaces and now enables end-to-end interoperability. For the transport level, Continua has recently adopted the ZigBee Health Care Profile (http://www.zigbee.org/) and the Continua Bluetooth Profile in addition to Bluetooth Low Energy (BLE) and USBand the ISO/IEEE11073 Personal Health Device family of standards [4] for the data level.In the GiraffPlus project, we aim at deploying a number of sensor devices that are pervasively integrated in the home or that can be used by the elderly to collect vital signs measurements.

The difference with the end-to-end architecture of Continua is that we are interested in a holistic view of the home environment, and we aim to collect information potentially coming from devices belonging to different application domains: personal health devices, home automation devices, entertainment devices, smart energy management devices, and so on. The novelty of our approach is in the integration of existing sensors into one system aimed at providing increased home safety and in supporting monitoring physiological parameters over a long period of time. The acquisition of physiological data will include the reliability of non-invasive data acquisition methods and the reliable detection and filtering of measurement artifacts. In wireless GSK-3 sensor networks (WSNs), data aggregation, fusion and filtering are an important topic and combined with aspects, such as security, robustness, reliability and extended lifetime, are very challenging. The level of complexity increases even more considering that sensed data may be originated by subsystems having different constraints and using different protocols.