How Were EKG Machines Invented – A Brief History of the Electrocardiogram
The origins of the EKG machine can be directly correlated with the discovery of electronic potential within living tissue. First investigated in 1878 by Italian scientist Aloysio Luigi, the “electromotive effect” proved that human muscle tissue is capable of generating its own electricity. But it wasn’t until 1856 that Willem Einthoven observed the electronic potential of the heart. When he later invented the galvanometer, the first functioning EKG machine was born.
Einthoven’s string galvanometer was simply a string, which when suspended in a magnetic field and exposed to the current of the heart, recorded its deflections on a piece of photographic paper. It wasn’t long before large-scale manufacturing of the EKG machine began throughout Europe. The revolutionary machine wasn’t introduced in the United States until 1909. The Hindle Instrument Company was among the first to manufacture EKG machines for the U.S. market.
Since then many major improvements have been made to the design of EKG machines, with one of the most important ones being a smaller electromagnet. Later, it was learned that the electrodes could be attached directly to the patient’s skin instead of immersing their limbs into a sodium chloride solution. Amplifiers were later added, which improved the detection of the electronic signal.
Today’s EKG machines incorporate many of these original elements in their design, but they’ve also added computer interfaces and software that automatically analyzes and stores the results. Wireless networks have also allowed ECG data to be transmitted immediately to another facility for further analysis. But as modern and convenient as these modern machines have become, they are no more accurate in detecting the heart’s electrical signals than Einthoven’s original EKG.
