This book provides those working with medical-technical equipment on a daily basis, with a better understanding of the underlying principles of such equipment. It also explains how to recognize potential hazards. The book is centered around that equipment used most often in hospitals. The author does not assume in-depth knowledge in engineering sciences, physics and mathematics, and avoids the use of jargon. The objective throughout the book is to help the reader achieve a better understanding of medical-technical equipment, and to reduce the incidence of user-caused accidents.