Types of medical stethoscopes and phonendoscopes - areas of application and advice on selection. Stethoscope and phonendoscope: the difference between medical devices

If you need a stethoscope, then you need to choose a device that will help you work faster and better. The choice of a stethoscope is a purely individual matter, depending on hearing capabilities and purposes of use. A doctor who works with children may need a different model of stethoscope than a doctor who works with adults.

The ideal stethoscope is one that provides clear, loud sound, comfortable, looks great.

So, what should you pay special attention to when choosing a stethoscope, so that the stethoscope becomes a faithful and reliable friend in your work for many years?

Material

Stethoscopes are made from various materials - plastic, aluminum, stainless steel. Aluminum stethoscopes are lightweight but make less accurate measurements. The head of a good stethoscope should be made of perfectly machined stainless steel. Such a stethoscope may cost a little more, but this is necessary for a tighter fit of the device to the patient’s body, without the entry of excess air. A stethoscope is like a drum, and any air leak, even a small one, can lead to loss of sound quality.

Membrane

The membrane must be made of high quality flexible material. The main problem with cheap stethoscopes is often the quality of the membrane (diaphragm). The denser the membrane, the higher its natural vibration frequency and the better it transmits high-frequency sounds. Cheap stethoscopes have a diaphragm that does not fit well to the body, making it difficult to detect minor body noises. The ability of a membrane attachment to capture sounds is directly proportional to its diameter. A large-diameter nozzle better captures low-frequency sounds.

Tube

The stethoscope tube should be made of thick material, preferably with a large internal double hole. This improves sound transmission and isolates external noise. The thicker the tube, the better it eliminates extraneous noise. Vinyl tubing is preferable to rubber tubing. Tubes with an internal diameter of 4.6 mm provide better sound transmission.

Thin tubes are more flexible, the hole size is smaller, which causes limited sound transmission, distortion, and the addition of extraneous sounds.

The shortest length of tubes at which in the best possible way high-frequency sounds are heard and which does not interfere with work is 30 cm. The best compromise between the ideal 30 centimeters and the length of conventional commercially available stethoscopes, equal to 50-55 cm, are 37.5 cm tubes.

Ear tips

The tips are hard (made of plastic) and soft (made of rubber). Hard tips do not change their shape, while soft tips adapt to the shape of the external auditory canal. Rigid eartips, which are positioned straight rather than at an angle, are less comfortable to use, can be painful to use, and allow sound leakage. Using soft tips is much more convenient. The ear tips should be positioned slightly at an angle. It is important that the ear tips seal the ear canals tightly and tightly.

We figured out the structure of the stethoscope. Now let's see what types of stethoscopes there are. For clarity, after describing each type of stethoscope, I give examples of real stethoscopes that are popular among specialists.

Types of stethoscopes

Double Head Stethoscope:

Universal device general purpose
Diaphragm mode (designed to listen to high-frequency heart sounds)
Funnel or bell mode (designed to listen to low-frequency lung sounds)
The stethoscope head can be rotated

Microlife ST-72

Low price
- Designed to listen to the sounds of the heart and other organs

Stethoscope Little Doctor Prof-III

Low price
- Designed for pediatricians
- In demand, despite low quality materials and poor acoustic sensitivity.

Stethoscope with easily adjustable aperture

Allows you to listen to low and high frequency sounds
No need to remove the head from the patient's chest
To obtain low-frequency sounds, the user needs to press the membrane slightly against the patient's body; to obtain high-frequency sounds, the user needs to press the membrane more tightly
Modern model stethoscope is very popular

Affordable price
-Excellent acoustic sensitivity, loud, clear sound
-Suitable for medical students and practicing doctors
-On one side of the head there is a classic funnel, and on the other there is a patented dual-frequency adjustable diaphragm, which makes it possible to listen to high and low frequencies without turning the stethoscope head over.

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-Steel head
-The head has only a membrane, which operates in funnel mode when pressed lightly, and in aperture mode when pressed tightly
-Saves time, gives good acoustics, has a thin elegant design, not heavy.

Welch Allyn Harvey™ DLX

It has three working heads: a funnel, a diaphragm, a head with a “grooved” diaphragm
- The grooved diaphragm enhances sound and is suitable for “overview” auscultation
- Has phenomenal acoustics
- A small diameter funnel allows for auscultation in hard-to-reach places.

Single Head Stethoscope:

A popular type of stethoscope among cardiologists for monitoring heart sounds
Has a wide frequency range
Double tube inside the head provides clear, pure sound

Microlife ST-71

Low price
- Designed for listening to heart sounds, measuring blood pressure
- It is popular despite its weak acoustic capabilities.

Sprague Rappaport:

From the ears there are two separate tubes, fastened together with special clamps. The tubes are connected to the head of the stethoscope
The tubes can rub against each other and create extraneous noise.
This stethoscope looks unusual, but is becoming less popular

Omron Sprague Rappaport

Low price, availability
- Clear, loud sound
- Extraneous noise
- Suitable for beginners

Electronic stethoscope:

The acoustics of the stethoscope have poor amplitude, sound transmission is not accurate
Most electronic stethoscopes are a simple sound amplifier with headphones.
Cheap material and design do not justify the high price of the stethoscope
An electronic stethoscope can increase sound volume by 10 times compared to an acoustic stethoscope.
Ideal for doctors with hearing problems. But they can cause hearing damage. For example, if a doctor was listening to a child and he suddenly screamed. Enhanced sound may damage the doctor's hearing.
Battery operated, many models have a warning system to let the doctor know when the battery is low. If the battery is low, the electronic stethoscope can be used as a regular acoustic stethoscope.
Some models have a small digital display that shows the battery status, heart rate, and sound volume level. They produce models of electronic stethoscopes that have special ports and can be connected to other stethoscopes, computers, electronic devices. Several people can listen to the patient at the same time, and the sounds obtained as a result of listening can be saved.

It amplifies the sound many times (more than 20 times). But not everything is as wonderful as it might seem at first glance, since the smallest noises from microscopic movements are also amplified
- By using digital processing sound reduces external noise. Great feature when recording sounds
- The ability to record audio fragments, transfer them to a computer, listen to them again, process, analyze.

Pediatric stethoscope:

Designed for working with children. Has a smaller membrane.

Littmann(R) Classic II S.E Infant

Designed for listening to newborns and children up to one year old
- Easily adjustable membrane for listening to high- and low-frequency sounds without turning the stethoscope head over
- Available in a wide range of colors

Littmann(R) Classic S.E. II Pediatric the same as the Littmann(R) Classic II S.E Infant model, but is intended for listening to children from 1 year of age.

On at the moment a new, more advanced line of classic Littmann stethoscopes - Classic III - has been released

Fetal stethoscope:

Stethoscope for pregnant women. Designed to listen to the fetus
It is shaped like a listening tube and is placed on the woman’s stomach during the examination.
Models of electronic stethoscopes for pregnant women are being produced
It is used both in antenatal clinics and at home by expectant mothers in order to hear the baby’s heartbeat and the sounds of its vital functions.

What else is important to know

It is necessary to carefully monitor the cleanliness of the stethoscope: wipe with alcohol or soapy water. The device should not be immersed in liquids or steam sterilized.

A stethoscope should not be worn around the neck. Perfumes can have a detrimental effect on the stethoscope tubes and destroy them.

Online store 120-80 presents phonendoscopes, stethoscopes, stethophonendoscopes at the most favorable prices in the country! What is their difference? Read on.

On the pages of our website, you can buy a phonendoscope different types and different brands: Microlife; C. S. Medica; B.Well; Little Doctor et al.

What is the difference between a stethoscope and a phonendoscope?

Using a stethoscope, you can listen to a person's internal organs. It looks like an elongated tube with different ends: wide and more concave. Through the concave end, the doctor, leaning his ear, listens to the internal organs. A phonendoscope is a more advanced version of a stethoscope. It has an amplifying, tightly stretched membrane that is sensitive to the slightest sound vibrations.

Modern doctors use such a measuring device as a stethoscope. It is a type of tube with a socket and a membrane for listening to sound vibrations. In everyday life, a stethofonendoscope can be called a phonendoscope, a stethoscope, but, as a rule, it always means the most advanced version of these devices.

Phonendoscope prices can vary, it all depends on the brand and quality of the device. The catalogs of the online store 120-80 contain only the best medical devices.

Our website presents various types of devices: classic (Y-tube); rapport; obstetric; pediatric; cardiological.

A stethoscope is an important working tool for every general practitioner, because it allows you to listen to noise in the lungs, bronchi, intestines, heart and even blood vessels. The device helps to detect extraneous wheezing and noise, which allows timely medical assistance.

In the 120-80 online store you can buy a stethoscope of any model and choose the most reasonable price for yourself. All products presented in our catalogs are made of durable, wear-resistant material that meets sanitary standards and requirements.

Instructions

A phonendoscope is absolutely necessary in the work of a therapist. With its help you can listen to peristalsis in the intestines. In cases where the patient complains of abdominal pain and bloating, it is important for the doctor to determine whether food is moving through the intestines. To do this, the doctor places a phonendoscope in the umbilical area and on the sides of the abdomen. Based on the characteristic sounds of peristalsis, the therapist determines the degree of intestinal function (active, passive); rumbling may indicate flatulence.

The cardiologist necessarily uses a phonendoscope of the heart and large vessels. Using this instrument, you can hear pronounced heart murmurs that occur due to defects. It is also important to use a phonendoscope to listen to the rhythm of the heartbeat and determine the clarity of the sound. With pathological work of the myocardium, an indistinct sound will be heard. By auscultation, the doctor can determine the time between systole and diastole.

Using a phonendoscope, you can listen and evaluate the filling of large vessels with blood. Using the “figure of eight” rule, the doctor places the head with the membrane of the instrument first on the skin at the site of the aorta, then in the projection of the large arteries, and ends the examination by auscultation of the superior and inferior vena cava in the places where they flow into the atrium. Of course, by listening with the device, the doctor determines only severe pathology; to clarify the diagnosis, there are other examinations - ECG, ultrasound of the heart and blood vessels, ECHO, etc.

A phonendoscope is necessary for auscultation of the lungs and bronchi. By applying this device to the chest, the doctor can hear crepitus and wheezing due to an inflammatory process in the respiratory organs. With this device you can listen to wet breathing or not, find the “non-functioning” lobe of the lung during pleurisy, identify the source of the greatest inflammation, i.e. determine right-sided or left-sided pneumonia. To confirm the suspected diagnosis, the doctor prescribes more informative methods examinations – chest X-ray, bronchoscopy.

A pediatrician needs a phonendoscope for a general examination of a child. Using this device, a pediatrician evaluates lung function and counts heartbeats and respiratory movements per minute. For ease of counting, some phonendoscope models have a built-in clock with a second hand.

The kit with non-automatic tonometer models must include a phonendoscope. With its help, the rhythmicity of the filling of the artery in the elbow bend is heard when measuring blood pressure. First, air is pumped into the tonometer cuff, then the valve on the bulb relaxes slightly and air begins to escape from the cuff, at this time it is necessary to listen to the beats in the artery using a phonendoscope. The first beat determines the systolic pressure. And according to the latter, diastolic.

Stethoscope and phonendoscope. Story

Yeah! As soon as they don’t call what the doctor places on the patient’s chest or back - stethoscope, phonendoscope or stethophonendoscope. And here is a mechanical tonometer. How do we listen to the brachial artery? Stethoscope or phonendoscope? It is written: “Tonometer with built-in stethoscope” - so there’s no difference?

But there is a difference.

And there is a fascinating story about Napoleon Bonaparte’s doctor, Rene Laennec, who in 1816, due to internal delicacy, could not put his ear to the chest of a sick young girl, and, in order to spare her modesty, began to listen to the heart and lungs with notes rolled into a tube. Lo and behold, the sounds were stronger. This is how the stethoscope was born - from the Greek words stethos - chest, and skopeo - I observe.

And only at the beginning of the 20th century - almost 100 years later, the Russian surgeon Nikolai Sergeevich Korotkov (it was he who invented the auscultatory method of measuring pressure), improved it by stretching a membrane over the bell - and called this instrument a phonendoscope.

What is the difference between a stethoscope and a phonendoscope?

Mainly high-frequency sounds (lungs, blood vessels) pass through the phonendoscope membrane, and low-frequency sounds (heart, intestines) pass through the funnel: the low frequencies seem to drown out high-frequency vibrations.

The membrane of the stethoscope significantly reduces the volume of all sound and the low frequencies become very quiet. At the same time, high frequencies become clearly audible

As we see the difference between a stethoscope and a phonendoscope in terms of application: With the membrane of a phonendoscope we listen to the high tones of the lungs and blood vessels, and with the bell of a stethoscope we listen to the low frequencies of the heart or intestines.

The differences between a stethoscope and a phonendoscope are visible to the naked eye.

5 and 6 - Stethoscope head

The stethoscope consists of a head: on one side there is a “bell” (5), and on the other there is a membrane (6), a sound-conducting tube (4), a tee (3), a headband spring (a metal plate connecting the headband tubes. It is not shown in the figure ), headband tubes (2) with olives (1).

The acoustic data of the stethoscope depend on the internal shape and design of the head used by manufacturers.

What you need to know about stethoscopes and phonendoscopes

The price of a good stethophonendoscope ranges from $90 to $200. A lower price indicates lower quality.

About the design: The head material can be different - plastic, aluminum or stainless steel. The best material is well-processed stainless steel. It is important that the stethoscope fits tightly to the patient’s body and that no air gets in - any air leak leads to losses in sound transmission.

The membrane, or diaphragm, must be flexible, durable and fit snugly to the body.

The thicker the stethoscope connecting tube, the better. Moreover, vinyl tubes isolate external noise better than rubber ones.

Studies have shown that the ideal length of a stethophonendoscope tube is 30 cm with an opening diameter of 4.6 mm. But on sale we see tubes of less quality in sound, but more comfortable, 50-55 cm long.

Compromise tube length 37.5 cm

Headband tips (or olives) are hard plastic and soft rubber or gel. The latter, of course, are better, since they adapt to the shape of the user’s ear canal.

The metal tubes of the headband can be connected by a metal tension spring, which certainly improves the usability.

Stethoscope heads can be single, double (bell/membrane), double diaphragm (large diameter/small), double with fluted head

Currently, Littmann has also invented heads with a tunable or dual-frequency membrane: To hear the low frequencies (bell mode), lightly apply acoustic head to the patient.

For listening high frequencies you need to press the head tightly: the movement of the diaphragm membrane becomes limited. Low-frequency sounds are blocked and high-frequency noises become audible

Littmann stethoscopes can have two adjustable diaphragms - a large one for adults and a small one for children.

In addition, there are stethoscopes for infants and young children, as well as fetal stethoscopes for pregnant women to listen to the fetus.

Currently, the classic version of the stethoscope is the stethophonendoscope, which combines a funnel (like a stethoscope) and a membrane (like a phonendoscope) in its double-sided head. In general, phonendoscopes and stethophonendoscopes are called “stethoscope”.

When visiting a doctor, the doctor always examines us, using various medical devices and instruments. Let's try to figure out what the difference is between a stethoscope, a phonendoscope and a stethophonendoscope. So, a stethoscope (from ancient Greek στηθοσκόπιο, from στῆθος “chest” + σκοπή “examination”) is an elongated tube in the form of a thin hollow cylinder, one end of which is wider than the other and has a concave shell for the ear. The doctor puts his ear to the wide end of the stethoscope and listens to the patient’s internal organs (lungs, heart, bronchi, intestines, etc.) for extraneous noise and drones.

For the first time, an analogue of a stethoscope, which was just a folded piece of paper, was used for auscultation* of the heart.

The stethoscope was invented in 1816 by the French physician, founder of scientific diagnostics, René Théophile Laennec. In his work he wrote:

“I was invited in 1816 to consult a young lady who had general signs of heart disease and in whom application of the hand and percussion, due to her fullness, gave little information. Since the age and gender of the patient did not allow me to use direct listening, I remembered the well-known acoustic phenomenon: if you put your ear to the end of a stick, you can very clearly hear a pinprick made at the other end. I thought it might be possible to use in this case this is a property of bodies. I took a notebook of paper and, twisting it tightly, made a tube out of it. I applied one end of the tube to the region of the patient’s heart, and to the other end I applied my ear, and I was as amazed as I was satisfied to hear the beating of the heart much clearer and more distinct than I had ever observed by direct application of the ear. I then suggested that this method could become a useful and applicable method not only for the study of heartbeats, but also for the study of all movements that can cause noise in the chest cavity, and, consequently, for the study of breathing, voice, wheezing and perhaps even vibrations of fluid accumulated in the cavities of the pleura or pericardium.”

But since then, the stethoscope has changed significantly, undergoing a number of changes.

As for the phonendoscope (from the Greek φωνη - “sound”, ’ένδον - “inside” and σκοπέω - “I observe”), it is a more modern stethoscope. Its main advantage over its ancestor is that with the help of a phonendoscope you can listen to high-pitched sounds due to a tightly stretched membrane, which is sensitive to sound vibrations and amplifies them. It is noteworthy that the term “phonendoscope” was proposed by the Russian scientist Nikolai Sergeevich Korotkov**.

And now a few words about the stethophonendoscope. As you probably already guessed, a stethophonendoscope is a combined version of a stethoscope and a phonendoscope. This device allows you to listen to both low and high sounds. This is what modern doctors use.

The stethoscope consists of three main parts:

sound receiving device - head (capsule) with a membrane,
tube that conducts sound
tips for doctor's ears (olive).

In everyday life, a stethophonendoscope is often called simply a stethoscope or phonendoscope, meaning this modern modified version.

* Auscultation (from Latin auscultatio) is a method of physical diagnosis in medicine, veterinary medicine, and experimental biology, which consists of listening to sounds produced during the functioning of internal organs. Auscultation is of two types: direct and indirect. Direct - involves putting the ear to the organ being listened to, and indirect - is done using special devices.

**N.S. Korotkov (1874-1920) - Russian surgeon, in 1905 invented a method for measuring blood pressure.

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