Since the beginning of human history, people have been keeping track of the vital signs of one another by using a variety of techniques to record information such as the rate at which the heart beats, the temperature of the body, the rate at which the lungs breathe, and the blood pressure in the arteries. In this article, Gleamed explores the origins of Patient Monitoring Systems, traces their development over the course of several centuries, and investigates the capabilities of modern patient monitoring systems.