 | Stethoscope: Encyclopedia - Stethoscope
Stethoscope
The stethoscope (Greek στηθοσκόπιο, of στήθος, stéthos - chest and σκοπή, skopé - examination) is an acoustic medical device for auscultation, i.e. listening to internal sounds in the human body. It is most often used to listen to heart sounds and breathing (breath sounds), though it is also used to listen to intestines and blood flow in arteries and veins.
Stethoscope - History
The stethoscope was invented in France in 1816 by René-Théophile-Hyacinthe Laennec. It consisted of a hollow wooden tube and was monoaural. In 1851 Arthur Leared invented the binural stethoscope which has become the standard ever since. By 1873, there were descriptions of a differential stethoscope that could connect to slightly different locations to create a slight stereo effect, though this did not become a standard tool in clinical practise.
Fetal stethoscope
Stethoscope - Current practice
The stethoscope is used in aid of diagnosing certain diseases. The stethoscope is able to transmit certain sounds and exclude others. Before the stethoscope was invented, doctors placed their ear next to the patient's body in hope of hearing something.
Stethoscopes are often considered as a symbol of the doctor's profession, as doctors are often seen or depicted with a stethoscope hanging around their neck.
Stethoscopes are also used by mechanics to isolate sounds of a particular moving engine part for diagnosis.
Stethoscope - Types of stethoscopes
Acoustic stethoscopes are familiar to most people, and operate on the transmission of sound from the chestpiece, via air-filled hollow tubes, to the listener's ears. The chestpiece usually consists of two sides that can be placed against the patient for sensing sound – a diaphragm (plastic disc) or bell (hollow cup). If the diaphragm is placed on the patient, body sounds vibrate the diaphragm, creating acoustic pressure waves which travel up the tubing to the listener's ears. If the bell is placed on the patient, the vibrations of the skin directly produce acoustic pressure waves traveling up to the listener's ears. The bell transmits low frequency sounds, while the diaphragm transmits higher frequency sounds. This 2-sided stethoscope was invented by Rappaport and Sprague in the early part of the 20th century. The problem with acoustic stethoscopes is that the sound level is extremely low, making diagnosis difficult.
Electronic stethoscopes overcome the low sound levels by amplifiying body sounds. Currently, a number of companies offer electronic stethoscopes, and it can be expected that within a few years, the electronic stethoscope will have eclipsed acoustic devices.
Stethoscope - Methods of examination
- Physical examination
- Inspection
- Palpation
- Percussion
See also
Stethoscope - External link
- BBC: Smart stethoscope for detecting kidney stones
Categories: Medical equipment | Medical testing equipment | Medical tests
Other related archives1816, Fetal stethoscope, France, Greek, Inspection, Medical equipment, Medical testing equipment, Medical tests, Palpation, Percussion, Physical examination, René-Théophile-Hyacinthe Laennec, auscultation, breath sounds, breathing, heart sounds, intestines, medical
 Adapted from the Wikipedia article "Stethoscope", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki |
