History of the ECG Machine

The modern day ECG machine is a breakthrough in the field of medical science. This machine is used daily throughout the world saving lives. Modern hospitals simply could not function with out them. The ECG machine that we see today has evolved over the years from a very basic device that was used to measure electricity. This device was known as Galvanometer which was developed in the year 1749.

Ten years later, in the year 1849, Dubois-Raymond enhanced the existing measuring device to measure the current. This device was known as Rheotome.
In 1868, Raymond's student, Julius Bernstein modified the rheotome, so that the simulation and sampling could be varied. This was called as the differential Rheotome. This was the first kind of ECG machine of that time. It was experimented on frog hearts, by measuring their heartbeat using two electrodes. This was the birth of the Electro Cardiograph Machine as we know it today.

Due to lack of sensitivity which lead to the further advancement in the design and Capillary electrometer was developed by Gabriel Lippmann in 1872.

Augustus De'sire waller was the first one to discover that the capillary electrometer can measure the electrical activity of the human heart without opening the chest. The firs electrical activity of the human heart was recorded in 1887. It was initially called as cardiogram and later Einthoven named it as Electrocardiogram.

Einthoven began to work his work on ECG in 1900.The first improvement in the capillary electrometer was the invention of string galvanometer in 1903. The first ECG machine introduced in the US was the string electrocardiograph that was developed by Cohn in 1909.

The first machine in the US was designed by Horatio Williams and built in 1914 by Charles Hindle. On May 20, 1915, the machine traced the electrical activity of the human heart for the first time. The next improvement was done on the electrodes. The size of the ECG was greatly reduced. In 1920, the strap on electrode was introduced by Cohn.. In 1932, Rudolph Burger introduced the suction electrode, which was later modified by Welsh as the suction cup that is currently in use with 12 lead machines.

The GE Corporation developed the vacuum tubes for amplification. The next CRT was introduced into electrocardiography. The introduction of the amplifier type electrocardiographs helped in improvement in recording the electrical activity of the heart.

As you can see, the ECG machine has come a long way from its early days measuring the stress of frogs!

matt @ ECG Machines