The book provides a well-structured introduction to the medical fundamentals and device technology for modern intensive care. Each chapter begins by laying the groundwork for understanding the respective physiology and relevant diseases. Following this, the specific therapeutic devices are described in terms of their functions, which can be used to treat the corresponding conditions. The focus is on modeling the interaction between machines and the body. At various points, this is complemented by a historical overview and a look at future developments, which in many cases point towards information fusion, networking, and automation, leading us to Cyber Medical Systems.