http://www.stethoscopeguides.com/

A stethoscope is a

medical

instrument used

to listen to sounds

produced in the

body, especially

those that

emanate from the

heart and lungs

The stethoscope is a very

important noninvasive tool used

by medical professionals and all

health care workers and

students will be trained in the

use of them.

A French doctor

named Rene-

Theophile-

Hyacinthe

Laennec

invented the

first

stethoscope in

1816.

This cylindrical

stethoscope is made

with three parts

fitting together by

wood screw thread

and brass tube

fitting with an

overall length

of 12.6 inches and a

diameter of 1.5

inches. Both ends

are slightly concave

Picture after the fresco by Theobald Chartran

in the Sorbonne commemorating the

invention of the stethoscope in 1816. The

photo on the right shows Laennec examining a

young boy by "mediate" auscultation with his

stethoscope. The picture is taken from a

painting by Robert A. Thom, copyrighted

in 1960.

In the early 1850's

there was a rush of

designs for a new

stethoscope that

used both ears. This

new

'Bi-aural' or

'Binaural'

instrument was felt

to be the future of

auscultation.

The idea belonged to Nicholas Comins , who

devised a stethoscope that he

described as "a bent tube" that had several

hinges, allowing the physician to not have to

assume

uncomfortable positions during the

examination. He offered the suggestion of

making his

instrument binaural, and may have, as there

are only sketches of his instrument.

Acoustic

stethoscopes are

familiar to most

people, and

operate on the

transmission of

sound from the

chest piece, via

air-filled hollow

tubes, to the

listener's ears

audible sounds are

magnified through

an amplifier to

earphones, of which

there may be more

than one set, and

may be broadcast

through

loudspeakers, but in

both instances the

results are mediocre

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