As diverse as tomorrow s society constituent groups may be they will share the common requirements that their life should become safer and healthier offering higher levels of effectiveness communication and personal freedom. The key common part to all potential solutions fulfilling these requirements is wearable embedded systems with longer periods of autonomy offering wider functionality more communication possibilities and increased computational power. As electronic and information systems on the human body their role is to collect relevant physiological information and to interface between humans and local and/or global information systems. Within this context there is an increasing need for applications in diverse fields from health to rescue to sport and even remote activities in space to have real-time access to vital signs and other behavioral parameters for personalized healthcare rescue operation planning etc. This book s coverage will span all scientific and technological areas that define wearable monitoring systems including sensors signal processing energy system integration communications and user interfaces. Six case studies will be used to illustrate the principles and practices introduced.