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Laënnec and the stethoscope: 1816-1819
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René Laënnec, a physician at the Necker Hospital in Paris, specializes in diseases of the chest. Two events in 1816 give him the idea for a significant contribution to medical practice.
Walking in a courtyard of the Louvre he sees children playing an acoustic game with a long strip of wood. A boy scratches one end of the wood; his friend, with the other end to his ear, hears the sound clearly. Soon after this Laënnec is visited by a female patient too plump for her heartbeat to be easily discernible but too young for him to press his ear to her chest with decorum. Following the example of the boys, he rolls a sheet of paper into a tube. He places one end gently on the lady's bosom and the other to his ear.
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Laënnec is surprised to discover that through the tube he hears the heart with much greater clarity than with his ear to a patient's chest. He has stumbled upon the principle of the stethoscope (from Greek stethos chest, scopein to observe).
Laënnec now constructs a hollow wooden tube, about nine inches long with ends designed to fit snugly against the chest and into the ear. He spends three years analysing the weird and often tumultuous sounds which reach him as patients breathe. At first he has no way of interpreting them. But he notes the variety of noises heard in terminally ill patients, and in subsequent post mortems he observes the condition of their lungs and heart.
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By this means Laënnec is able to identify and describe the characteristic sounds of various stages of bronchitis, pneumonia and - increasingly important as one of the most prevalent diseases of the 19th century - tuberculosis. Laënnec's researches are published in 1819 in Traité de l'auscultation médiate (Treatise on Mediate Auscultation). Auscultation, or listening to the body for diagnostic purposes, has until now always been 'immediate' - with the physician's ear pressed to the patient's body. The stethoscope becomes the mediating instrument.
Later in the century a tube of rubber is found to be more convenient. And in 1852 the familiar modern version is introduced, enabling the physician to use both his ears.
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Contact lenses: 1887
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A German physiologist, Adolf Fick, grinds glass lenses in 1887 to a very precise and unusual shape. They are to fit exactly over the surface of a patient's eyes. This pair of spectacles, instead of being supported on the nose, clings to the eyes themselves.
Contact lenses remain an oddity (and no doubt a very alarming one) until they begin to be made of plastic in the 1940s. Thereafter Fick's boldly simple idea proves its worth in a bewildering range of adaptations - such as soft lenses, extended-wear lenses, disposable lenses, lenses to change the colour of the eyes, and even bifocals.
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Sections Missing
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Sections are as yet missing at this point
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Page 10 of 11 |
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