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A string galvanometer is a sensitive fast-responding measuring instrument that uses a single fine filament of wire suspended in a strong magnetic field to measure small currents. In use, a strong light source is used to illuminate the fine filament, and the optical system magnifies the movement of the filament allowing it to be observed or ...
Before Einthoven's time, it was known that the beating of the heart produced electrical currents, but the instruments of the time could not accurately measure this phenomenon without placing electrodes directly on the heart. Beginning in 1901, Einthoven completed a series of prototypes of a string galvanometer.
The electrocardiograph was impractical to use until Willem Einthoven, a Dutch physiologist, innovated the use of the string galvanometer for cardiac signal amplification. [2] Significant improvements in amplifier technologies led to the usage of smaller electrodes that were more easily attached to body parts. [ 1 ]
Dutch physiologist Willem Einthoven developed the string galvanometer in the early 20th century, publishing the first registration of its use to record an electrocardiogram in a Festschrift book in 1902. The first human electrocardiogram was recorded in 1887, however only in 1901 was a quantifiable result obtained from the string galvanometer.
Williams traveled to Holland to study the methods of Willem Einthoven in 1911. [ 2 ] He constructed the first string galvanometer in America, pioneered vectorcardiography , discovered the ventricular vulnerable period, and first determined the 60-Hz current required to produce ventricular fibrillation with body-surface electrodes.
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Economists have estimated that Swiss economic output could be reduced by 1% if severe amplification effects like a trade war broke out or companies started relocating to avoid tariffs.
In 1897 a French electrical engineer, Clement Ader, invented the "string galvanometer", containing a tensioned string of quartz. In 1903, Einthoven modified Ader's machine, adding electrodes attached to the patients limbs and thorax. In use the string was seen to vibrate in time with the patients heart. The vibrations were recorded ...