Stethoscope
The stethoscope is a diagnostic tool for the assessment of sound phenomena.
His name means ' chest monitor or measuring device ' and has been neoclassical formed by its inventor René- Théophile- Hyacinthe Laënnec in French as stéthoscope and borrowed from French into German (Greek στῆθος STETHOS ' breast '; double -scope, German - skop, Greek σκοπός Skopós ' guardian ' ), thereby demonstrating, although it is actually a " Stethophon " is how the visual component dominated in the former medical examination technique.
The operation of the interception is known in the medical terminology auscultation. In mechanical engineering, the stethoscope is also used to detect early example via an incipient bearing noise machine damage can.
In human and veterinary medicine are with the stethoscope sounds and noises assessed, incurred in connection with the activity of the heart, lungs and intestines. For each physical examination includes auscultation of the heart valves and sometimes the carotid arteries to exclude pathological flow noise or continuous guided pathological heart murmurs. When the blood pressure measurement using a stethoscope to listen to the Korotkoff flow noise.
A binaural stethoscope with a dual diaphragm chestpiece is referred to Nikolai Sergeyevich Korotkov as phonendoscope, a but nowadays hardly used term.
Types
Acoustic stethoscopes
Stethoscopes today are acoustic or classical stethoscopes that make through simple physical phenomena body sounds easier to hear. Simple stethoscopes are made of wood, funnel-shaped ear trumpets. They are still used in prenatal diagnosis and called Pinard tube.
The most commonly used stethoscopes consist of three basic elements: earloop, hose and brisket (or " head"). The brisket is a membrane which receives the acoustic waves is thereby set itself to vibrate and passes these on to the column of air in the stethoscope tubing. About the earhook the waves are directed at the eardrum of the examiner. The attached at the end of the ear hook " olive " of hard or (better) soft plastic seal off the ear canals. We call this stethoscope also flat-head stethoscope.
In some models, the breast piece can be rotated through 180 °. Alternatively, the side with the membrane, there is a funnel without membrane. This allows a better view of the hopper the lower frequency spectrum. Particularly in cardiology relevant. This stethoscope is called dual head stethoscope, the head itself is called a dual-head chest piece. Furthermore, there are dual head stethoscopes having a membrane on the second page, but with a smaller diameter for the study of small bodies.
A special diaphragm design some stethoscopes can on the contact pressure of the membrane emphasize different frequency ranges depending. At low pressure, as the funnel, emphasizes the low frequencies, at higher pressure the higher-frequency sound waves.
Valid acoustic quality differences within the classic, purely mechanical stethoscopes can not be proved in metrological and objective comparisons. A possible short, stiff hose and seal well olives for shielding noise are for the auscultation of advantage that demonstrate the elaborate attempts by Sprague and Rappaport, which were carried out by them in the first half of the 20th century. According to Sprague, a Boston cardiologist and Rappaport, his technical engineer, the stethoscopes are named Sprague - Rappaport offered today numerous than replica. The invention of the " combination stethoscope ", consisting of a double-headed chest-piece with a funnel on one side and a diaphragm on the other hand, goes back to David Littmann. This can be since then listen to high - and low-frequency sounds better. 1963 he announced his development to the patent. The price range for mechanical stethoscopes is generally very large, brand stethoscopes cost to far above 100 EUR.
Stethofork
The Stethofork is a commonly used in the hearing aid classic Stethoscope without chestpiece. The open end of the hose Stethoclips can be placed directly on the angles of the hearing aid and allows an almost störgeräuschfreies interception of the art sound without losses through filters or membranes.
Electronic Stethoscopes
Various stethoscope manufacturers now offer even electronic stethoscopes - the amplify sound electronically, emphasize different tones and noise ( such as ambient and friction noise) are eliminated. Sounds can also be recorded and played back or sent to a computer. Currently these types of stethoscopes still not very common, which is partly due to the sometimes very high cost.
History
Developed the stethoscope in 1816 by René Théophile Hyacinthe Laënnec in France. Since he did not, as was customary, was about to put his ear directly on the chest of a patient, he used a roll of paper as " ear trumpet ". After he had found that he heard so not bad, but even better, he drove the development of the stethoscope, first in the form of wooden Hörrohres to advance.
The illustrated ear trumpets from the 19th century are described in Meyers Lexicon as follows: " The stethoscope is a 26-31 cm long tube of wood, designed funnel-shaped bottom, and at the top of a circular disk, called the ear plate is usually made of ivory, mounted. The lower end of about 2.6 to 3.9 cm in diameter, shall be rounded to make it to the body skin does not cut painful at touchdown. In use, you take the stethoscope on the funnel-shaped end, puts it exactly on the surface of the body part, which is to be examined, so that it is seated firmly all around, and then put your ear to the ear plate. "
Today's technology auscultation goes back to the Austrian physician Josef Škoda (1839 ).