This article is more than 5 years old. Information may no longer be current.
Auscultation and the stethoscope
Click Here to Manage Email Alerts
The stethoscope is considered to be the first diagnostic tool introduced into modern medicine. From the Greek words stethos meaning chest and skopien meaning to observe, the stethoscope is one of the most universal and enduring symbols of the medical profession.
Originally designed as a way to put distance between the physician and a patient, today it is one of a decreasing number of diagnostic tools that provide intimate doctor-patient contact. Some physicians even question whether this 19th century relic still has a practical place in medicine.
Regardless of its future in the industry, the stethoscope was a revolutionary invention that allowed physicians to eavesdrop on the inner workings of the human body.
Early diagnostic method
The use of thoracic percussion was among the early methods used for examination of the chest. Introduced in 1761 by Leopold Auenbrugger, a Viennese physician, percussion involved tapping a patient’s chest with a finger and interpreting the sound. Auenbrugger had seen his father gauge the level of beer and wine in barrels by tapping the barrel. He adapted this technique and found that percussion could be used as a diagnostic tool for diseases of the chest.
Another method sometimes used by physicians was direct auscultation. A physician would place an ear to a patient’s chest to listen for sounds of the heart or lungs.
Despite their usefulness, auscultation and thoracic percussion both received little widespread attention. In 1808, Napoleon’s physician, Jean-Nicholas Corvisart, would popularize both methods. He translated Auenbrugger’s work into French, published it and began teaching it to his students.
One student, Rene Laënnec, was not satisfied with the diagnostic precision of either method. If a patient was overweight or obese, the resulting sounds were sometimes inaccurate or muffled. In some cases, a patient’s cleanliness could be a concern, and when treating women, placing an ear to the chest was often considered improper.
|
Source: The National Library of Medicine |
A new invention
In 1816, faced with the examination of an overweight woman, Laënnec combined these techniques with a general knowledge of acoustics to create an early version of what would later be the stethoscope. He rolled a piece of paper into a tight cylinder to listen to the heart and lungs of the patient.
Laënnec placed one end at the patient’s precordial region and the other to his ear. Doing this, he was able to hear the beating of the heart with greater clarity than ever before. He called the new method mediate auscultation.
Laënnec spent the next few years experimenting with different types of wood, ivory and other materials but finally settled on deal, a soft wood, for his new instrument. The first design of the stethoscope was wooden, about one foot long and 1.5 inches in diameter.
In 1818, Laënnec reported his findings to the Academy of Science and in 1819, he published De L’Auscultation Médiate, etc (On Mediate Auscultation), which described methods of using the stethoscope to listen to the sounds of the body. Laënnec was able to give accurate descriptions of many diseases of the chest — bronchiectasis, emphysema, pneumonthorax, lung abscess, hemorrhagic pleurisy — in greater detail than ever before.
Widespread use
In 1828, Pierre Adolphe Piorry reduced the diameter of the stethoscope from 1.5 inches to about the width of a finger. His design had a cone-shaped chest piece that tapered into a thinner ear piece. This allowed for a better seal at the physician’s ear.
The next major modification was made by Charles James Blasius Williams in 1843. His design had a cone-shaped chest piece that attached to a connection with two bent lead pipes. This was the first attempt at a binaural stethoscope.
George Philip Camman is credited with a design of the stethoscope most closely resembling its modern look. In 1855, he published an account of a stethoscope that had flexible woven tubing, a wooden chest piece, ivory ear pieces and a rubber band to hold the stethoscope in place on the physician’s head.
Although the use of the stethoscope was widespread by the beginning of the 20th century, many physicians claimed and still believe that the usefulness of the instrument as a diagnostic tool is dependent on the physician’s ability to interpret what is heard. As more advances in noninvasive imaging are made, the use of a stethoscope in modern medicine is less practical than it once was. Yet almost every physician still has one. Whether slung around the neck, or stashed in the white coat pocket, it is a symbol of the profession that endures. – by Leah Lawrence
For More Information:
- Bishop PJ. Evolution of the stethoscope. J R Soc Med. 1980;73:448-56.
- Jarcho S. Auenbrugger, Laennec, and John Keats: some notes of the early history of percussion and auscultation. Med Hist. 1961;5:167-172.
- Markel H. The stethoscope and the art of listening. N Engl J Med. 2006;354:551-552.
- Pinkerton JHM. Kergaradec, friend of Laennec and pioneer of fetal auscultation. Proc R Sec Med. 1969;62:477-483.
- Roguin A. Rene Theophile Hyacinthe Laennec (1781-1826): The man behind the stethoscope. Clin Med Res. 2006;4:230-235.
- Salomon B. What the stethoscope said. Ann Intern Med. 2001;135:56-57.
- Wilkins RL. Is the stethoscope on the verge of becoming obsolete? Respir Care. 2004;49: 1490-1497.