Introduction to the special section on Pervasive Healthcare

P ERVASIVE healthcare may be defined from two perspectives: first, as the application of pervasive computing—or ubiquitous computing, proactive computing, ambient intel-ligence—technologies for healthcare, health, and wellness management; second, as making healthcare available everywhere , anytime—pervasively. Essentially, pervasive healthcare addresses those technologies and concepts that integrate health-care more seamlessly to our everyday life, wherever we are. Weiser, the father of the ubiquitous computing, stated " the most profound technologies are those that disappear " [1]. Pervasive computing may be considered as the opposite to virtual reality: While in virtual reality the user enters the world created by computers, in pervasive computing, it is the computing that enters the physical world and bridges the gap between the virtual and physical worlds. This bridging is perhaps best described by means of its three most important enabling technologies: ubiquitous computing, ubiquitous communication, and intelligent user-friendly interfaces. Ubiquitous computing refers to the concepts like disappearing computer, " when they are everywhere, " and pervasive computing, and means integration of computing power (microprocessors) and sensing (sensors) into anything, including not only traditional computers, personal digital assistants (PDAs), printers, etc., but also everyday objects like white goods, toys, houses, furniture, or even paint (" smart dust "). Ubiquitous communication, in turn, means enabling anytime, anywhere communication of anything with anything else, not only people but also artifacts such as those listed above. Central technologies in ubiquitous communication are ad-hoc networking and wireless communication technologies—including low-power low-range communications. Intelligent user-friendly interfaces enable natural interaction and control of the environment by the human " users, " or inhabitants of the ambient environment. The interfaces support natural communication (speech, gestures), take into account user preferences, personality, and usage context, and enable multisensory interaction. The envisioned pervasive computing infrastructure, hence, provides a seamless environment of computing, networking, and user interfaces. The infrastructure is aware: It has senses and it has the required intelligence to interpret the sensory information—it is context-aware. The advances in these technologies during the last decade have already changed our daily life in many ways. Today, we are ubiquitously connected to our friends, colleagues, and information sources with our cellular phones. Our digital cameras may print their pictures directly on a nearby printer. Our children's toys include microprocessors and sensors, etc. In many ways, pervasive computing technology already plays a major role in people's everyday life. One of the most important application areas for pervasive technologies is …