A Survey of Applications of Wireless Sensors and Wireless Sensor Networks <s> D. Human-centric applications <s> Despite enormous progress in networking and computing technologies, their application has remained restricted to conventional person-to-person and person-to-computer communication. However, continual reduction in cost and form factor is now making it possible to imbed networking - even wireless networking - and computing capabilities not just in our PCs and laptops but also other objects. Further, a marriage of these ever tinier and cheaper processors and wireless network interfaces with emerging micro-sensors based on MEMS technology is allowing cheap sensing, processing, and communication capabilities to be unobtrusively embedded in familiar physical objects. The result is an emerging paradigm shift where the primary role of information technology would be to enhance or assist in "person to physical world communication via familiar physical objects with embedded (a) micro-sensors to react to external stimuli, and (b) wireless networking and computing engines for tetherless communication with compute servers and other networked embedded objects. In this paper we present the application of sensor-based wireless networks to a "Smart Kindergarten that we are developing to target developmental problem-solving environments for early childhood education. This is a natural application as young children learn by exploring and interacting with objects such as toys in their environment. Our envisioned system would enhance the education process by providing a childhood learning environment that is individualized to each child, adapts to the context, coordinates activities of multiple children, and allows continual unobtrusive evaluation of the learning process by the teacher. This would be done by wirelessly-networked, sensor-enhanced toys and other classroom objects with back-end middleware services and database techniques. We explore wireless networking, middleware, and data management technologies for realizing this application, and describe challenges arising from ad hoc distributed structure, unreliable sensing, large scale/density, and novel sensor data types that are characteristic of such deeply instrumented environments with inter-networked physical objects. <s> BIB001 </s> A Survey of Applications of Wireless Sensors and Wireless Sensor Networks <s> D. Human-centric applications <s> This paper describes the concept of sensor networks which has been made viable by the convergence of micro-electro-mechanical systems technology, wireless communications and digital electronics. First, the sensing tasks and the potential sensor networks applications are explored, and a review of factors influencing the design of sensor networks is provided. Then, the communication architecture for sensor networks is outlined, and the algorithms and protocols developed for each layer in the literature are explored. Open research issues for the realization of sensor networks are also discussed. <s> BIB002
Health science and the health care system can also benefit from the use of wireless sensors. Intel's research concerns senior citizens and their problems [27] . Cognitive disorders, which perhaps lead to Alzheimer's, can be monitored and controlled at their early stages, using wireless sensors. Intel in Portland and in Las Vegas is carrying out such an experiment (Proactive Health Research). The nodes can be used to record recent actions (taking medication, last visitor, etc.) and remind senior citizens, indicate the person's real behaviour, or detect an emerging problem. Related research, conducted by Intel and the University of Washington, uses RF ID tags to examine patient behaviour and customs by recording the frequency with which they touch certain objects. The application includes a display, which will help the "caregiver" extract information about the indisposed person discreetly and without hurting their feelings. Finally, motes can also be used in order to study the behaviour of young children. For example, the aim of the study reported in BIB001 was to analyse children behaviour, by monitoring sensors enclosed inside toys. Another medical application refers to human vision restoration  by retina prosthesis. Sensors are implanted to human organs to support a function and they require the capability to communicate wirelessly with an external computer system, which carries out the advanced processing. Energy limitations do not allow this computing to be carried out on-board the sensors. Other applications of wireless sensors to healthcare that have been proposed include tracking and monitoring doctors and patients, or tracking drug usage inside hospitals BIB002 .