This is a portable electrocardiograph (ECG or EKG); a machine that essentially prints out a visual representation of a person’s heartbeat. Electrocardiography refers to the process of recording the electrical activity of the heart. This particular machine was made in the 1950s. The first recording made with an EKG machine was in the mid 19th century, of a frog heart, with the electrodes placed directly on the heart. In 1872 there was the first-ever heart recording without the need for opening the chest. The early EKG machines weighed about 600 pounds. This particular, more portable, model was made by the Sanborn manufacturing company, which was founded by Frank Sanborn in 1917 and bought by Hewlett-Packard in 1961.