Stethoscopes
Created | Updated Mar 5, 2002
It is amazingly difficult to picture a doctor without his stethoscope. The stethoscope has become synonymous with medical practice. It is more than a mere heartbeat measuring apparatus, and some doctors will even tell you that it is a remarkable source of security when their job is not so easy.
The Origin of the Stethoscope
The stethoscope was invented in 1816 by Rene Laennec. Before this, doctors listened to the noises made by organs by placing an ear against the patient's body. Laennec was examining an obese young woman, and felt it would not be proper to put his ear against her bare chest to listen to her heartbeat, so he listened through a rolled up newspaper instead. Afterward, he said, "I was surprised and pleased to hear the beating of the heart much more clearly than if I had applied my ear directly to the chest." This gave him the idea for his invention.
His first stethoscope was a hollow, wooden tube. Several other designs were made after his, some with steel tubes, others with ivory, etc. Eventually, a "binaural" design was made with two earpieces. In 1850, George Camman thought of using rubber instead of the less flexible materials used in earlier designs.
Anatomy of the Stethoscope
Today's stethoscopes still have two ear pieces. These are attached to hollow rubber tubing which is connected to the body contact piece. There are several types of body contact pieces. To detect high pitched sounds, a doctor will use a diaphragm contact piece, whereas a bell contact piece is used to hear low pitched sounds. A doctor can also use a combination bell-diaphragm contact piece to discern sounds of a mediocre pitch.
The Usefulness of the Stethoscope
Stethoscopes can detect noises made by certain organs of the body such as the heart, lungs, intestines, and blood vessels while excluding all other sounds. Just as it was first intended to, the stethoscope decreases the physical contact between doctor and patient that can make for uncomfortable circumstances. It can also be of comfort to the patient because it denotes the professional stature of the doctor.
With the development of new technologies, doctors rely much less on the stethoscope, but it has not been discarded. Though it can detect a myriad of bodily noises made by various organs, today it is mostly used to detect sounds of the heart. A heartbeat makes what is described as a "lub-dup" sound. The "lub" sound is caused by the mitral and triscupid valves closing. When the blood exits the heart, the aortic and pulmonary valves close, causing the "dup" sound.
Some heart conditions may change the shape of the heart causing abnormal sounds. These sounds a called "heart murmurs" and are often described as "whooshing, rasping, or blowing" noises.
Will the Stethoscope Disappear?
Most likely, not for a long while. Though there are more sophisticated diagnostic methods, the stethoscope remains the most convenient and obviously the least expensive. Even if it is replaced with some other innovative tool, its impact on the medical practice will still be felt. The stethoscope has led to much clearer definitions of the normal sounds made by some organs, as well as better understanding of abnormal sounds, and thus, more concise descriptions of a myriad of diseases.