Before the development of the stethoscope, physicians performed their examinations using percussion and immediate auscultation – “listening” to the various organs. They often had to place an ear directly on the patient to perform this examination. While it was the most effective diagnostic technique at the time, because the sound wasn’t amplified doctors could miss critical sounds that might indicate illness. It could also be a little awkward for both doctor and patient.
French doctor René Laënnec of the Necker-Enfants Malades Hospital was attempting to diagnose a young, female patient who was reportedly “laboring under general symptoms of a diseased heart.” Laënnec tried using percussion – tapping on the chest – to see if fluid was present around the heart. Unfortunately, this particular patient was on the heavier side, and the “great degree of fatness” (Laënnec’s words, not mine) made it impossible to gain any diagnostic insight. Because the patient was so young, he also had reservations against putting his ear to her chest.In this painting by Theobold Chartran, Laënnec examines a patient in front of his students at Necker Hospital.
His solution was to roll up a sheet of paper to use as an aural tube, in the effort to make auscultation easier. It worked like a charm – Laënnec was clearly able to hear the patient’s heart. (No word on the patient’s diagnosis, unfortunately this fact was eclipsed.)
Thus, in 1816 the stethoscope was born. Laënnec decided to name it as such because it derives from the Greek stethos (“chest”) and scopos (“examine, inspect, look at”). The original model, merely a hollow, wooden tube with one earpiece, was called “Le Cylindre.”
In 1826, Laënnec became ill while studying tuberculosis, and asked his nephew to listen to his chest with his own invention. Unfortunately, his nephew heard the sounds that Laënnec had heard a thousand times in dying patients. A few months later, Laënnec died of tuberculosis, ironically becoming aware of his fate with his own invention.
Stethoscopes didn’t become bi-aural (two earpieces) until 1851, invented by Irish physician Arthur Leared. A year later American physician George Cammann refined the design for commercialization. Some were concerned that a bi-aural stethoscope might bring about hearing imbalances, which could cause some issues during examinations. By the early 1900’s this had not proven to be problematic, and stethoscopes became a common diagnostic tool.
During the 20th century, minor improvements to the devices reduced weight, improved acoustic quality, and were designed to filter out external noise. Electronic versions inevitable began to emerge, to further amplify the sound. Now, peripherals are being developed to further the functionality of the stethoscope – most recently a device that adds ECG monitoring and real-time digital analysis.