From the earliest days of medicine the study of the pulse has been of major interest to physicians, and trained observation of the pulse at the bedside has been of fundamental importance in diagnosis and in treatment. The quality of the pulse gives information about the condition of the heart and arteries, and, in former years, was supposed to reflect specific abnormal bodily states. Up to 100 years ago, the practicing physician paid little attention to pulse rate, but indulged in hairsplitting refinements of classification of pulses of different qualities. Innumerable voluminous but sterile treatises have been published on the quality of the pulse. Quantitative studies of the pulse rate were initiated by Galileo (1620), who synchronized the beat of a pendulum with the pulse and expressed the pulse rate by the length of the pendulum. One hundred years later, Sir John Floyer published a book, called the "Physician's Pulse