This book presents a detailed introduction to the fundamental principles and applications of biomedical instrumentation. It is intended as a textbook for the undergraduate students of Instrumentation, Electronics, and Electrical Engineering for a course in biomedical instrumentation as part of their programmes. The book familiarizes the students of engineering with the basics of medical science by explaining the relevant medical terminology in simple language. Without presuming prior knowledge of human physiology, it helps the students to develop a substantial understanding of the complex processes of functioning of the human body. The mechanisms of all major biomedical instrumentation systems--ECG, EEG, CT scanner, MRI machine, pacemaker, dialysis machine, ultrasound imaging machine, laser lithotripsy machine, defibrillator, and plethysmograph--are explained comprehensively. A large number of illustrations are provided throughout the book to aid in the development of practical understanding of the subject matter. Chapter-end review questions help in testing the students' grasp of the underlying concepts.