关键词：虚拟现实；生物医学；人体生物系统
摘 要：The introductory chapter begins with the basic definitions of virtual reality, virtual presence and related concepts. It provides an overview of the history of virtual reality, from its origins in the 1950s to the present day. It also covers some of the most important applications, from flight simulators to biomedical uses. Finally, it briefly describes the main feedback loops used in virtual reality and the human biological systems used to interpret and act on information from the virtual world.