Electrocardiograph

• Year of manufacture: 1908, Szikla Dezső Medical Surgical Instrument and Bandage Manufacturer, Budapest.
• operates: diluted sulfuric acid, mercury
• weight: 1.15 kg

To reconstruct the memoir of the first electrocardiograph we must dig back to the cradle of electricity fervent with experiments and rivalry. Gabriel Lippmann, a Luxembourg physicist, examines the relationship between electrical and capillary phenomena. In 1872 he introduced his capillary electrometer. The machine consists of a thicker and thinner capillary tube filled with mercury and diluted sulfuric acid, to which platinum wires are attached. Its operation is simple: the electrical pulse increases the mercury surface tension and the mercury level rises. When the tension decreases, the mercury level restores. Increases, rises. Decreases, restores. This irrelevant detail will be of a greater importance: the sensitivity of the method is suitable for the compensation observation of low potential difference electric forces.
Fifteen years later, in 1887, Aberdeen-based physiologist Augustus Desiré Waller, fuelled by a sudden idea begins a strange experiment. He applies Lippmann’s capillary electrometer – with the aid of his bulldog, Jimmie – to showcase the electric waves created by the heart. While Jimmie stands in a saline solution, the electrode taped to his chest picks up the weak impulses reaching the skin surface, which are then amplified by the electrometer and recorded on a paper strip. Thus he creates the first cardiogram that he presents in many lectures, but its medical application is received with scepticism not only by the animal right activists of the Royal Society, but is shrouded in doubt by Waller himself.
The as yet unforseeable significance of his experiment is recognized by British cardiologist Lewis Thomas and Dutch physiologist Willem Einthoven. Once Waller is also persuaded, they begin developments. Fourteen years later, in 1901, Einthoven creates the first electromagnetic ECG device. According to this system, the electrical activity of the contraction of the upper coronary atria is indicated by the P wave, the contraction of the lower heart chambers is indicated by the Q, R, S, and T waves. During the QRS time duration the heart’s main electric axis is the average of the integral vector. It is is averaged with two derivation approaches (R-Q-S) and then the values are recorded in the so-called Einthoven Triangle. Perpendiculars are set on the endpoints of the vectors, then the intersection of the perpendiculars from the starting points are connected to those from the endpoints. The result is the well-known curve recorded on a 25 mm/s paper-driven cardiogram that gives an accurate picture of transition of electrical impulses, abnormal waves, and irregular heart rate. The behemoth equipment from being a subject of ridicule slowly became the scientific milestone for the diagnosis of heart disease and with its miniaturaziton an indispensable component of modern medicine. Twenty-three years later, in 1924, Willem Einthoven was awarded the Nobel Prize in Physiology and Medicine.