Even if the stethoscope is often presented as the spontaneous brainchild of René Théophile Hyacinthe Laennec (1781-1826), there is a longer story behind this 1816 invention.
When Docteur Laennec rolled up a notebook in order to better listen to a patient’s chest, it seemed to have been done on impulse. But the idea for such “mediate auscultation” must have been growing in his mind for a long while.
“As an expert in Latin and Greek and a student of Napoleon’s personal doctor, Jean-Nicolas Corvisart, he knew that centuries earlier Hippocrates had listened to the human body by pressing his ear to a patient’s chest,” Professor Jacalyn Duffin told Medical Expo in an interview. She holds the Hannah Chair in the History of Medicine at Queen’s University in Kingston (Canada).
“Being sensitized to sounds through his love for music and an expert in anatomy, Laennec got his chance during his first job at the Necker-Hospital in Paris,” said Duffin, author of To See with A Better Eye: A Life of RTH Laennec.
EXPLORING THE CHEST
The examination of the rather plump woman patient, whose body could not be analyzed with the relatively novel practice of percussion (invented by the Austrian Leopold Auenbrugger), triggered the discovery. Laennec’s desire to listen to the sounds within her body while remaining at an appropriate distance from her was the ultimate catalyzer for the invention.
However, the 1949 French movie Dr. Laennec led generations of movie-goers to believe that he had been inspired by children playing with a solid wooden log in the courtyard of the Louvre. But this event was only one of the steps on the road to the first stethoscope, whose Greek name means “exploring the chest.”
“The actual discovery was not the instrument itself, but rather the observation that the acoustics of the chest could be heard through the tube,” explained Duffin. The young physician not only proved that a mediator transmits sounds but also interpreted and named them.
“This was a revolution and a major contribution to the further evolution of medicine. Laennec finally made anatomy relevant to medicine, and it became a course in medical schools after his discovery.”
BUY A STETHOSCOPE FOR 2 FRANCS
No wonder that the concept quickly traveled around the world, that auscultation became common medical practice and that Laennec’s first book, Traité de l’auscultation, published in 1819, became a success. Eager readers could buy a stethoscope (initially made by the inventor, himself) for only two additional francs.
The development of the new device continued. In 1840, British doctor Golding Bird introduced the first flexible monaural tube. This was followed in 1852 by the flexible binaural stethoscope by American physician George P. Cammann, which funneled sound to both ears instead of one.
James M. Edmonson, chief curator at the Dittrick Medical History Center in Cleveland (U.S.) told MedicalExpo that today “the most widely used modern stethoscope is the Littmann model, introduced in 1960.”
However, an essential driver was the need to sort out the meaning of heart sounds. Following Étienne-Jules Marey’s catheterization of the animal heart in 1861, the stethoscope’s use in cardiology pushed the invention to another level of relevance, said Prof. Duffin. Duffin has read thousands of manuscript pages written by Laennec: letters, medical records and his lecture notes for another book. Unfortunately, the exceptional doctor did not have the chance to publish it before his early death at the age of 45