Long before the invention of the electrocardiograph where many test to prove that electricity could be used to stimulate muscle contractions. These muscle contractions where first noted, in 1664 by Jan Swammerdam, when he had dissected a frog and noticed that the muscles began to twitch when a severed nerve was stimulated with a scalpel. Later, in 1668, Swammerdam continued his experiments with muscle contractions and nerve conduction. His experiment begun by suspending a muscle attached to a hook inside of a glass tube. He then added a water droplet and stimulated the nerve ending with a silver wire. This experiment had produced a muscle contraction, which was thought to have been caused by a small electrical charge, but it was never known for sure. From there, in 1745, Pieter van Musschenbroek had discovered that a jar partially filled with water and a nail protruding from the top could produce an electrical charge. The jar had later been named the “Leyden Jar” and was used in 1746 to send an electrical current through 180 Royal Guards. As time went on the use of an electrical current on the human body became more abundant, which eventually lead to the invention of the galvanometer.
The galvanometer was an instrument used to measure and record electricity. It was invented by Johann Schweigger in 1820. Schweigger had found that the effects of a magnetized needle in an electromagnetic field, was multiplied when bending an electric wire into a coil. By 1843 a more sensitive galvanometer had been produced, by Emil Du bois-Reymond, and was later used to confirm that electrical currents follow each heart contraction. Over the years the galvanometer continued to become more improved and the functions of the heart where becoming more clear.
Then in 1887 a man by the name Augusta D. Waller, recorded the first electrocardiogram on a human. He had recorded it with a capillary electrometer.
Finally in 1903, came the invention of the electrocardiogram by Wilhelm Einthoven, and by 1905 Einthoven was transmitting electrocardiograms from the hospital to his laboratory.
Einthoven had also recorded electrocardiograms with his string galvanometer which included left and right ventricle hypertrophy, along with atrial flutter and heart blocks. The string galvanometer had become a success and was later bought by Edward Schafer of the University of Edinburgh in 1908 for clinical use. After that, the string galvanometer was later purchased by others and continued to evolve into a better performing machine throughout the years. Eventually, the machine became smaller and different versions have been produced up until today’s time. One of those, called the Holter Moniter, is an ECG machine that is worn by the patient as they continue their daily activities. This device is simply attached to the chest with adhesive electrodes and then connected to the machine. It is used to record the hearts rhythm for a longer period of time outside of the clinic or hospital....