The human ear can detect sounds whose frequency varies from 16 to 20,000 vibrations per second.
Infrasound is a low-frequency sound wave (that is, with a frequency below 16 vibrations), ultrasound is a high-frequency sound wave with a frequency of over 20 thousand vibrations. They are not perceived by the human hearing aid and require the use of special instruments to detect them.
It was the huge number of studies that analyzed the signs of a sound wave and the effects of ultrasound that contributed to the emergence of prerequisites that made it possible to use ultrasound on a large scale in various industrial sectors, in the production of certain medicines, in medicine, physics, modern military technology, biology, the national economy and everyday life. life. Let's take a closer look at the effect of ultrasound on the human body.
What is ultrasound?
Ultrasound is a high-frequency mechanical wave that is inaccessible to human hearing, which can perceive vibrations in the range from 16 to 20 kHz.
Its properties are unique:
- capable of spreading in gaseous, liquid and solid media;
- can be natural or artificial;
- thanks to it, animals, birds and insects can navigate in space at any time of the day;
- due to it, dolphins and whales can send signals over long distances;
- used in various industries and fields of science.
Ultrasound - effects on humans
Mechanical vibrations occurring in an elastic medium, the frequencies of which vary from 16 to 20 kHz, are ultrasound. The human ear is not capable of perceiving such vibrations.
In industry, ultrasound is especially necessary for cutting, drilling, cleaning product surfaces from various impurities, welding metals, operating turbines, jet engines, etc. In agriculture, it is used as a repeller against rats, mice and insects. In medicine, ultrasound is used to diagnose pathologies and provide therapeutic physiotherapy.
During an ultrasound, the frequency of ultrasonic waves reaches 10 MHz. This is a safe indicator that is easily tolerated by people and does not have a negative effect on the body. The main thing is to adhere to certain time frames. Lower frequencies heat the body, causing tingling and numbness in the upper and lower extremities. At the same time, the harm of ultrasound cannot be compared with its benefits. Thanks to him, it is possible to examine the picture of the patient’s internal organs, carry out therapy for joints, nervous system disorders and neoplasms.
Therapeutic physiotherapy procedures are widely used, in which ultrasound influences a specific affected area. The duration of one procedure should not be more than 3-5 minutes, and the total duration of the procedure on several zones should not be more than 15 minutes. Over the course of three months, ultrasound therapy is allowed 12 times.
When the ultrasound frequency is greater than 120 dB, the human body is at risk. First of all, this concerns the human central nervous system (CNS). Therefore, the work of health workers and ultrasonic device technicians at enterprises becomes dangerous.
Therefore, everyone should monitor and remember the number of ultrasound therapy sessions performed so as not to harm their health. For example, you will have to give up cosmetic peeling for 2-3 months if the patient underwent physical procedures for the treatment of joints, spine or ultrasound.
Workers who constantly interact with ultrasonic devices must follow certain rules.
The equipment must be kept in an isolated room, and your hands must be protected with two gloves, both cotton and rubber.
The influence of ultrasonic waves on the human body
The effect of ultrasound on the human body at high frequencies disrupts the functioning of the nervous system:
- fatigue;
- headache;
- sleeplessness at night;
- drowsiness during the day;
- increased sensitivity to sounds;
- nervousness;
- low blood pressure;
- decreased hearing acuity.
Is ultrasound harmful to humans?
The effect of ultrasound on the human body is characterized by changes that occur depending on the dose of exposure. At small doses up to 90 dB, a stimulating effect occurs, that is, microscopic massage using vibration, as well as acceleration of metabolic processes.
At high doses of 120 dB or more, damage occurs.
Depending on the applied dose of mechanical vibrations, as well as the power, ultrasound acts on tissue differently:
- oppresses;
- stimulates;
- destroys.
Ultrasound is not harmful to humans; if a certain frequency and time are observed, positive therapeutic results can be achieved.
For medical purposes, ultrasound is considered completely safe.
Thanks to him you can:
- in traumatology, detect internal bleeding;
- in obstetrics, assess the development of the fetus and its parameters, as well as find out the gender;
- in cardiology, examine the cardiac and vascular system.
Use of Ultrasound in Medicine
The therapeutic effect of ultrasound is due to its ability to penetrate tissue, warm it up and provide micromassage. It should be noted that ultrasound probably has a number of specific effects, since deep heating of tissues is achieved through other methods, but a positive effect in some cases occurs only after using ultrasound.
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Taking into account the reflex mechanism, ultrasound can be used not only to directly influence the epicenter of pain, but also to influence it indirectly.
Thanks to the properties mentioned above, ultrasound, under a number of conditions, can have a bactericidal, antispasmodic, anti-inflammatory and analgesic effect. The use of ultrasound can be combined with other therapeutic techniques. Due to increased biological activity, care must be taken when treating with ultrasound. Positive results from its therapeutic use have been obtained in a number of diseases. It is very effective in the treatment of neuralgia, myalgia, neuritis of amputated limbs, periarthritis, arthritis and arthrosis. Many people are interested in whether ultrasound is harmful to humans.
Field of application of ultrasound
Ultrasound is used in various fields:
- metallurgical industry;
- chemical industry;
- agricultural industry;
- textile industry;
- food industry;
- pharmaceutical industry;
- instrument-making and machine-building industry;
- petrochemical and processing industry;
- military industry;
- medicine;
- dentistry;
- cosmetology;
- biology;
- everyday life
Application of ultrasound in medicine
In medicine, several frequency ranges are used for various purposes:
Ultrasound range | Application |
High, 1-20MHz. | Ultrasound diagnostics and surgery. |
Medium, 0.7-3 MHz. | Physiotherapy with thermal action. |
Low, 20-200KHz. | Therapy based on the mechanical influence of ultrasound: dentistry, eye surgery, liposuction, sonophoresis, sonothrombolysis. |
In medicine, ultrasound therapy can cure many diseases:
- skin – acne, furunculosis, dermatitis and others;
- ophthalmic – conjunctivitis, keratitis, blepharitis and others;
- dental – stomatitis, periodontal disease, gingivitis and others;
- cardiac and vascular - angina pectoris, hypertension, varicose veins, etc.;
- musculoskeletal system – arthritis, dislocations, osteochondrosis and others;
- nervous system – radiculitis, headaches, insomnia and others;
- respiratory system – bronchitis, pneumonia, tracheitis and others;
- ENT organs – tonsillitis, sinusitis, rhinitis and others;
- Gastrointestinal tract – cholecystitis, gastritis, ulcers and others;
- genitourinary system – cystitis, prostatitis, vaginitis and others.
Application in cosmetology
The influence of ultrasound in dermatology and cosmetology is characterized by skin changes. Devices operating on the basis of ultrasonic vibrations for cosmetic purposes are used for facial cleansing.
The influence of ultrasound on the human body in cosmetology
They have no harmful effects, since they operate at certain frequencies that are harmless to the human body. Thanks to ultrasound in cosmetology, it is possible not only to influence the surface of the skin, but also to change its pathological condition.
Ultrasound in cosmetology has the following effects:
- healing;
- bactericidal;
- anti-inflammatory;
- anesthetic;
- antispasmodic;
- general tonic.
Ultrasound also stimulates:
- hemodynamics;
- lymph flow;
- regenerative processes.
Thanks to ultrasound, it is possible to improve the functioning of internal organs, which has a positive effect on the change in dermatological diseases.
Application in dentistry
The effect of ultrasound on the human body at low frequencies in dentistry prevents the development of diseases:
- gingivitis;
- stomatitis;
- periodontal disease;
- periodontitis and others.
Also has a therapeutic effect:
- improves drug absorption;
- has a detrimental effect on microorganisms;
- cleanses tissues from infections;
- stops bleeding;
- has a directed effect against tumors;
- has a gentle effect on soft tissue;
- has contactless cleaning.
Ultrasound preparations in dentistry are used in various directions:
- hygiene procedures are carried out using an ultrasound scanner;
- using an ultrasonic scalpel, pulpitis and deep caries are treated;
- physiotherapeutic treatment based on ultrasound together with anti-inflammatory medications is used after implantation or complex tooth extraction;
- using ultrasound during dental prosthetics, bridges and crowns are sanitized;
- Thanks to ultrasonic washers, reusable instruments are efficiently processed.
Harm of ultrasound
Is ultrasound harmful to humans? This diagnostic method is not irradiating, since it differs from the principle of operation, in which some dose of radiation penetrates the body. Ultrasound is just a certain amount of sound vibrations. Waves cannot accumulate in the body.
Therefore, we cannot talk about poisoning here. A person can only have a negative impact through regular contact with this diagnostic tool. When it is turned off, the negative impact stops. To use it safely, you must follow the recommended testing schedule.
Doctors say that routine ultrasound during pregnancy is not dangerous for the baby. It can also be used to examine young children or adolescents. The same can be said about other medical and cosmetic procedures that use high-frequency sound.
Video: is ultrasound harmful to humans?
How does ultrasound stimulate blood circulation?
Thanks to ultrasound therapy used in cosmetology and dermatology, several effects can be obtained:
Mechanical is a massage of cells at the microscopic level. Due to this, the permeability of the cell membrane increases. The thermal effect has vasodilation and increases blood flow.
As a result, beneficial substances penetrate into the cells of the unhealthy organ. Due to the chemical effect, cells produce enzymes, elastin, collagen, hyaluronic acid, which leads to a rejuvenating result.
Is ultrasonic teeth cleaning harmful?
Benefits of ultrasonic teeth cleaning:
- clears plaque;
- removes stone;
- whitens by 1-2 tones;
- disinfects the surface of teeth;
- increases resistance to caries;
- helps prevent gingivitis, stomatitis, and periodontitis;
- increases the sensitivity of enamel to calcium and fluoride.
In the absence of restrictions, professional ultrasonic teeth cleaning does not pose any danger. However, everything should be in moderation. The procedure is not recommended to be performed more than 2 times during the year.
More frequent use leads to thinning of the enamel and microscopic cracks. Although in special situations such as impaired mineral metabolism or high viscosity of saliva, the procedure is prescribed once every 3-4 months.
Treatment
If mild signs of asthenic syndrome and vegetative-vascular disorders appear, the person remains able to work. However, it is necessary to monitor his condition and provide treatment. A visit to a dispensary or sanatorium is recommended.
In more complex cases, you should transfer to a job that does not involve the use of ultrasound for 1-2 months. If strong neurodynamic and neurocirculatory changes are detected, problems with hearing and vestibular apparatus appear, in addition to appropriate treatment, it is necessary to change place of work.
Contraindications to the use of ultrasound
The most important limitations on the use of ultrasound are:
- oncological diseases;
- bearing a fetus;
- the presence of a prosthesis, pacemaker, implant;
- tuberculosis;
- autonomic neurosis;
- the presence of pustules or inflammation on the skin;
- general unsatisfactory condition;
- thrombophlebitis;
- period after radiotherapy.
Limitations associated with ultrasound facial treatment:
- inflammatory process of the maxillary sinuses;
- the presence of fillers based on polymeric materials;
- operations performed on the eyeball recently;
- the presence of gold and platinum threads;
- diseases associated with the optic nerve;
- facial nerve paralysis.
Restrictions associated with body procedures:
- the presence of an intrauterine device in the uterine area;
- the presence of stones in the gall bladder, kidneys and hepatic ducts.
Consequences of exposure to ultrasonic waves on the human body
The effect of ultrasound on the human body at high intensity causes the following consequences:
- increased pain;
- baldness;
- destruction of red blood cells of the blood system;
- clouding of the cornea and lens;
- an increase in the amount of uric acid, as well as lactic acid, and cholesterol in the blood system;
- minor hemorrhages of tissues and organs of the human system;
- significant hearing loss;
- destruction of nerve cells;
- pathology and disorder of bone matter.
Due to prolonged exposure to ultrasonic vibrations, the following symptoms may occur:
- frequent fatigue;
- dizziness;
- fast fatiguability;
- restless sleep;
- forgetfulness;
- indifference;
- uncertainty;
- lack of need for food;
- confusion;
- depression.
Symptoms of the harmful effects of ultrasound
People who frequently work with ultrasonic devices are at risk of harmful effects from ultrasound.
When affected by dangerous frequencies, the following problems occur:
- central nervous system disorder;
- restless sleep;
- memory losses;
- asthenia;
- nervousness;
- blockage in the ear canals;
- headaches;
- increased hyperesthesia to sound;
- face pale or red;
- icy hands and feet;
- fainting state.
In rare cases, there are:
- disruption of the natural functioning of the stomach, namely abdominal pain, a feeling of heaviness;
- disorders of a diencephalic nature, that is, thinness, hallucinations, increase in body temperature to 37.5 degrees, seizures;
- polyneuritis;
- disorder associated with the cardiovascular system.
There are 3 stages of change in the human body when exposed to ultrasonic waves:
At the initial stage, a slight change occurs:
- activity of the central nervous system;
- endocrine organs;
- vestibular disorders;
- vegetative polyneuritis.
At the moderate stage, the same changes occur as at the initial stage, only they are more pronounced. Moderate diencephalic changes also appear. At an advanced stage, symptoms of organic damage to the central nervous system appear, as well as a moderate change in the diencephalic character.
Influence
Ultrasound radiation itself is not dangerous or beneficial.
The harm and benefits of ultrasound depend on its use. Sound vibrations can have different frequencies and powers. That is why ultrasound can both cut granite and conduct research on pregnant women. The effect of ultrasonic waves on a person can be different. Prolonged exposure to ultrasound can lead to dire consequences. Penetrating through the environment of the body, waves can provoke oscillatory displacements, severe tissue damage, inflammation, and necrosis.
With intense exposure, even one-time radiation can have a destructive effect on cellular structures. That is why special protective equipment has been developed for people whose profession involves ultrasound.
Ultrasound is fundamentally different from radiography. During an x-ray, a certain portion of radiation penetrates into the human body, which over time can accumulate in the internal organs and cause harm to health. The ultrasound procedure does not produce radioactive radiation: the waves are generated by a medical device. These vibrations do not affect cellular structures, tissues and internal organs, since the intensity of the waves is minimal.
Ultrasound, unlike x-rays, does not harm human health. This allows you to safely use ultrasound beams to diagnose pregnant women and children.
However, a person working with an ultrasound device must carefully adhere to the rules for operating the equipment.
Is ultrasound dangerous for humans? Ultrasound radiation is a certain amount of sound vibrations that are not capable of accumulation inside the body. Only regular interaction with an ultrasound device can become harmful. By turning off the device, you can stop its influence.
With prolonged exposure, vibrations can affect some parts of the brain. Thus, specialists servicing an ultrasound machine often suffer from the following disorders:
- insomnia;
- increased aggressiveness;
- headaches;
- memory loss;
- deterioration of hearing abilities.
Persons in the wave propagation zone often experience numbness in their limbs, polyneuritis may develop, blood sugar levels may decrease, and there may also be a lack of vitamins. In addition, prolonged exposure to radiation on a person can cause redness or paleness of the face.
Doctors who perform diagnostics using an ultrasound machine most often:
- suffer from asthenic syndrome;
- experience hallucinations;
- lose weight;
- have endocrine diseases.
This is why ultrasound specialists receive a premium for harmfulness.
These manifestations are most often temporary and occur in the patient in cases where, for health reasons, he has to frequently visit the ultrasound diagnostic room.
By using this research method two or three times a year, at long intervals, you don’t have to worry about the consequences.
However, regular use or violation of the safety precautions of the device may cause some problems.
Treatment of complications from ultrasound waves and preventive measures
Therapy consists of eliminating symptoms and strengthening the patient's immune system.
At the initial stage of a central nervous system disorder, the following is required:
- regular supervision by a specialist;
- undergoing outpatient treatment;
- visiting medical complexes;
- employee suspension for 2 months. from ultrasonic equipment with transfer to another position that does not require interaction with these devices.
At a pronounced stage of the harmful effects of ultrasound, outpatient and inpatient treatment is required.
It is necessary to follow preventive measures that will help avoid serious damage to the body:
- ultrasonic devices must be located in a special room;
- in ultrasonic baths it is necessary to limit the contact of hands and detergents;
- parts on the equipment must be secured with a special mechanism;
- parts can only be unloaded and loaded when the ultrasound generator is turned off;
- Hands must be protected with appropriate gloves.
Prevention
To minimize the harmful effects of ultrasound, the following recommendations should be followed:
- Ultrasound equipment is best installed in isolated rooms.
- It is necessary to limit as much as possible the contact of hands with the liquid in ultrasonic baths and with the instrument while frequency vibrations pass through it.
- Loading and unloading of tools must be carried out with the equipment turned off.
- When working on machines, tool elements must be secured using certain devices.
- The worker should wear double gloves: first cotton and rubber on top.
Is ultrasound really harmful? The negative impact after using this diagnostic method in medicine has not been proven by scientists, so it is impossible to give an exact answer to this question. Currently, this is the safest method for studying human internal organs.
Professionals who regularly work with ultrasound equipment should adhere to safety regulations. Otherwise, various disorders may arise. Mostly, such problems are faced by people servicing powerful production or traction equipment. But technology developers take this into account and strive to minimize the danger posed by their tools.
The basic method for examining internal organs without surgery is ultrasound. From the beginning of the method until now, patients have been asking whether ultrasound is harmful to humans?
Ultrasound is necessary not only for medical purposes, but also in industry, agriculture, cosmetology and just in everyday life. To answer the question of why and to what extent ultrasound is dangerous for the body, you need to approach it from a scientific perspective.
Are household ultrasonic devices dangerous?
Ultrasonic devices, such as air humidifiers or rat and mouse repellers, do not pose a danger to humans. Because ultrasound does not pass through walls and furniture.
It is harmful only if you are close to the device, and also if you stay near it for a long time. It is for this reason that those people who work on ultrasound machines are paid a wage premium for hazardous work. Despite the fact that ultrasound at certain frequencies has no effect on the human body, safety measures must be observed.
Author: Belaeva Kristina
Article design: Mila Friedan
Ultrasound during pregnancy
Ultrasound examination during gestation is a standard procedure that must be performed at least three times over the entire 9 months. Is ultrasound dangerous during pregnancy? Recently, many women have refused such a study, as the belief has spread that ultrasound is extremely harmful to the fetus in the womb.
Large-scale studies have not been carried out on this matter, but some scientists talk about harm. Doctors argue that there are too few scientific studies to speak with confidence about the benefits and harms of ultrasound.
In this regard, one should not often resort to this diagnostic method unless absolutely necessary. The ultrasonic frequency definitely affects the baby and may even affect the formation of its organs. Research by P. Garyaev suggests that there is a possibility of gene mutation in the fetus.
Gynecologists consider ultrasound the most convenient and safe way of examination. It is carried out for the purpose of:
- Confirmation of pregnancy.
- Determining the duration of pregnancy.
- Exclusions of abnormal embryo development.
- Determining the sex of the child.
- Confirmation of fetal viability.
- Finding out the location of the placenta at the moment.
- Determining the biophysical state of the baby.
During pregnancy, ultrasound examination is an important method to ensure a good check of fetal development. The procedure allows you to maintain the health of the mother and her baby.
Video about ultrasound
Harmful effects of ultrasound on humans:
Ultrasonic waves have a wide practical application in various fields of human activity.
Devices with ultrasonic generators are used for medical diagnostic procedures, flaw detection, ultrasonic welding, in various production processes, etc.
In addition to the above, ultrasonic waves have found wide application in everyday life and are used to repel various pests: mice, rats, insects, etc.
For this purpose, special devices have been created - ultrasonic repellers, which are installed both at industrial facilities and used at home. In this regard, the “amount of ultrasound” in a person’s life has increased sharply.
Naturally, the question arises about whether the impact of ultrasound on the human body at work and at home is dangerous.
To give an affirmative answer to this complex question, you need to understand what ultrasonic waves are and how the ultrasonic repeller that a person uses in everyday life functions.
Harm of ultrasound, alternative methods | World Without Harm
In modern medicine today, almost no diagnosis is made without a preliminary ultrasound examination of the patient’s body or a specific internal organ.
We are, of course, not talking about colds, but to detect a serious defect or conduct a diagnosis for abnormalities in the development of the fetus - ultrasound devices cope with all these tasks with ease. However…
- Does such visualization harm the health of the patients themselves?
- On what principle do ultrasound diagnostic devices work?
What is ultrasound diagnostics?
Thanks to the use of special equipment (ultrasound transmitter), which emits high-frequency sound waves (they are not detected by the human ear and their frequency is 3.5 MHz), which, when they hit the object of study (internal organ), are reflected from it and returned to the receiving device called the receiver , which, in turn, interprets these waves into an image on the monitor.
So, in the case of an ultrasound examination of the fetus during pregnancy, they are reflected from the fetus, thereby allowing you to see not only the baby’s skeleton, but also its internal organs.
In the case of studying the internal organs of a person, sound waves are reflected from the surface of these organs and transmit information to the screen about the size, structure and deviations in the functioning of the organ being studied.
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Impact of ultrasound on humans
As for the very nature of the impact of ultrasonic waves on the human body, the question of benefit and harm depends on three factors:
- ultrasonic wave intensity,
- sensitivity of living tissues,
- time of exposure to such waves.
Medicine does not deny the fact that ultrasonic energy can cause harm to human health when its intensity exceeds 10 W/cm .
At such wave intensity, disturbances caused by tissue heating and cavitation processes (when gas bubbles are converted into liquid) are observed. However, the intensity of modern ultrasonic research devices is only 0.05 - 0.25 W/cm.
At these intensity levels, no tissue heating is observed. And, as for the processes of cavitation, there is no clear opinion.
Therefore, the harmlessness of ultrasound examination devices seems to be proven by science and medicine, but... some doctors who conduct such examinations throughout the working day, at the end of their shift, complain of a headache and a tingling sensation in the tips of their fingers... (For more details - the influence of ultrasound per person). ↑
The attitude of medicine to the influence of ultrasound
Taking all these facts into account, the National Institutes of Health in the United States of America has decided not to overuse this diagnostic method. This is especially true for pregnant women . And, in Japan, it was decided that ultrasound should not be prescribed to all patients, but only to those who have serious indications for this.
The question quite naturally arises, why is this so? Why do states and countries that have a high level of medical development, have all the necessary modern equipment for research, and master all the necessary techniques, suddenly treat ultrasound diagnostics with such caution? The answer is quite simple - the factor of unrecognized risk influences their excessive caution.
We have already said that the human ear does not perceive the frequencies that are used in ultrasound examinations, however,
- How can one explain the fact that during the diagnosis of pregnant women, the fetus reacts quite violently to such an intrusion into its mystery of development?
- What to do with the scientifically proven facts that ultrasonic waves negatively affect human chromosomes, and, in the case of ultrasound diagnostics of pregnant women, this can lead not only to a delay in the development of fetal growth, but also to its mutations?
Experiments conducted on animals have proven that ultrasound leads to changes at the microscopic level of tissue, which in the future leads to developmental abnormalities and defects .
But what about the strange pattern that
those mothers who performed ultrasound diagnostics more often than was actually required had babies born with low birth weight (by the first year of life they still caught up with their peers in terms of body weight, however...)
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When to do an ultrasound and when is it better to abstain?
Increasingly, our medicine is inclined to not subject itself to such a diagnostic procedure without serious indications, and if we do carry out ultrasound diagnostics, then examine a specific internal organ, and not the entire human body, for general development, so to speak... ↑
Alternative to ultrasound for pregnant women
Therefore, if it is possible to conduct studies of internal organs in another, alternative way, you should not rush to give consent to conduct this type of diagnosis.
So, for example, in the case of pregnant women (we most often think about them, because during the nine months of pregnancy they go through this procedure more often than other categories of the population), the fetal heartbeat does not have to be listened to during an ultrasound examination, for this You can use another, no less proven and truthful method - listening with a fetoscope. The same applies to the position of the fetus in the uterus - the hands of a competent obstetrician-gynecologist can easily determine how your child lies even without ordering an ultrasound... ↑
in “The impact of ultrasound on the human body - are ultrasonic repellers harmful? ”
I've always wondered how ultrasound repels pests and whether it's a scam. After reading the article, I wanted to buy and try an ultrasonic repeller in my home.
The human ear is capable of detecting sounds whose frequency is within the range of 16-20,000 vibrations per second. Low-frequency (infrasound; frequency less than 16 vibrations per second) and high-frequency sound waves (ultrasound; vibration frequency more than 20 thousand per second) are not perceived by the hearing aid, so a person uses special devices to detect them. Thanks to a huge number of studies, the purpose of which was to study the properties of ultrasonic waves and the effects of ultrasound, prerequisites arose that made it possible to widely use ultrasound in various industries, medicine, biology, modern military equipment, the national economy, in the production of certain drugs, in physics and in everyday life. life.
Characteristic
Ultrasound is mechanical vibrations with a frequency of more than 16-20 kHz, which are not detected by hearing. It is used in the following industries:
- In industry and agriculture: cutting, welding, surface cleaning, etc.
- In medicine: identifying many diseases.
- In cosmetology: skin cleansing.
- Used in the operation of large production machines: turbines, jet engines.
Generally, in industrial environments, the ultrasound frequency ranges from 20 to 70 kHz.
Ultrasound affects the health of medical workers when their hands come into contact with liquids and instruments. Many researchers believe that such frequencies can also negatively affect people through the air.
What is ultrasound
Ultrasound is a high-frequency sound wave (its vibration frequency exceeds tens and hundreds of thousands of hertz), capable of propagating in liquids, solid materials, and also in a gaseous environment due to the action of elastic forces.
Ultrasound has both artificial and natural origin. Thus, in nature, bats, dolphins, whales, butterflies, grasshoppers, locusts, crickets, and some species of birds and fish are endowed with sensory organs that allow them to reproduce and perceive vibrations created by an ultrasonic wave. Thanks to this, they can navigate well in space, including at night, and communicate with their relatives. Whales and dolphins can send information tens of thousands of kilometers away. They are also capable of detecting ultrasound from cats and dogs.
The speed of propagation and intensity of ultrasound are directly influenced by the properties of the substance in which it propagates: moving away from the source in the air, the sound weakens quite quickly; and, on the contrary, in liquids and when passing through solid matter its strength decreases slowly. Unlike ordinary sounds, which propagate from a source in all directions at once, ultrasound is a wave in the form of a narrow beam.
Thanks to these features, ultrasound is used to study the bottom of seas and oceans, detect submarines and sunken ships, as well as possible obstacles under water and determine the exact distance to them.
However, propagating in the aquatic environment, ultrasonic waves can also cause harm to the organisms living in it. Under the influence of ultrasound, fish float to the water surface with their bellies up, their sense of balance is sharply disturbed, and as a result they cannot assume a normal position for themselves. Prolonged intense exposure to ultrasound, exceeding permissible limits, ultimately leads to extremely severe damage, as well as the death of fish. In those cases where the effect of ultrasound is temporary and its intensity is low, after its cessation the behavior and lifestyle of the fish becomes the same.
Difference from normal sound
It differs from ordinary sound in that it travels in all directions from the source. Ultrasound is essentially a wave in the form of a narrow beam. Such features make it possible to use it for exploring the sea and ocean floor, detecting sunken ships and submarines, as well as various obstacles under water, and accurate distance.
But when propagating in water, ultrasonic waves can cause harm to the organisms that live in it. Under the influence of ultrasound, the fish's sense of balance is disturbed; they float to the surface of the water with their bellies up, and therefore cannot assume their normal position. If exposure to ultrasound is intense and prolonged, exceeding acceptable limits, it will ultimately cause very serious damage and even death to fish. If its influence is temporary and the intensity is not too high, after its cessation the lifestyle and behavior of the fish return to their usual framework.
The effect of ultrasound on the human body
Ultrasound affects humans in a similar way. During the experiments, water was poured into a cupped palm, and then the subject immersed his hand in the ultrasonic field. At the same time, he experienced unpleasant painful sensations. In general, we can say that the essence of the biological effects of ultrasound has not yet been fully studied. However, most likely, it is based on local pressures arising in the tissues and on the local thermal effect, directly related to the absorption of energy that occurs during vibration damping. Since liquids and gases can absorb ultrasound well, and solids can conduct it, the skeletal system of the human body is also a good conductor.
First of all, exposure to ultrasound provokes the occurrence of a thermal effect in a person, which is a consequence of the transformation of the energy of the ultrasonic wave into heat.
In addition, it causes microscopic compression and stretching of tissues (so-called micromassage) and stimulation of blood circulation. As a result, the functions of various body tissues and blood flow improve. Ultrasound can also have a stimulating effect on the course of metabolic processes and neuro-reflex action. Ultrasound causes changes not only in those organs that are affected by it, but also in other tissues and organs. At the same time, prolonged and intense exposure leads to the destruction of cell death. This is due to the fact that under the influence of ultrasound, cavities are formed in body fluids (this phenomenon is called “cavitation”), as a result of which tissues die.
The ultrasonic wave is also capable of destroying many microorganisms, which makes it possible to inactivate viruses such as polio or encephalitis. The effect of ultrasound on protein leads to disruption of the structure of its particles and their disintegration.
Under the influence of ultrasound, leukocytes and red blood cells are destroyed, and its viscosity and coagulability increases significantly, in addition, ROE accelerates.
Ultrasound has a depressing effect on cell respiration, reduces the amount of oxygen it consumes, and also promotes the inactivation of certain enzymes and hormones.
Exposure to high-intensity ultrasound can lead to the following consequences for humans:
- Baldness;
- The occurrence of severe pain;
- Clouding of the cornea and lens of the eye;
- Hemolysis;
- Increased levels of cholesterol, uric and lactic acid in the blood;
- Minor hemorrhages in various tissues and organs of the body;
- Serious hearing impairment;
- Destruction of cells of the organ of Corti;
- Destruction of nerve cells;
- Pathological development and destruction of bone tissue.
As a result of prolonged exposure to ultrasound, increased drowsiness, fatigue, dizziness, manifestations of vegetative-vascular dystonia (memory impairment, sleep disorders, indecisiveness, apathy, fearfulness, decreased appetite, tendency to depressive states, etc.) occur.
Harm of intense influence
In this case, intense and prolonged influence destroys cells and leads to their death. This is due to the fact that cavities are formed in body fluids under the influence of ultrasound (this phenomenon is called cavitation), which causes tissue death. An ultrasound wave can also destroy many microorganisms, and this helps inactivate viruses such as encephalitis or polio. The effect of ultrasound on protein causes a disruption in the structure of its constituent particles and their further disintegration. In addition, it destroys red and white blood cells in the blood, its coagulability and viscosity increase significantly, and ROE also accelerates. The ultrasound wave has a depressing effect on cellular respiration, reduces the amount of oxygen consumed by it, and causes the inactivation of a number of hormones and enzymes.
So the effect of ultrasound on the human body is still not very good.
Exposure to ultrasound for medical purposes
The healing properties of ultrasound are due to its ability to massage and warm tissue. However, the ultrasonic wave has a number of specific effects on the body. It is possible to deeply heat the tissue using various methods, but only the use of ultrasound can achieve good results in treatment.
In medicine, ultrasound is widely used not only to influence the source of pain, but also for indirect influence. This achieves the following effects:
- Painkiller;
- Antispasmodic;
- Anti-inflammatory;
- Bactericidal.
A combination of ultrasound exposure with other types of therapeutic therapy is allowed. However, treatment must be carried out with great caution. This is due to the high biological activity of the ultrasonic wave.
Overall Impact
The general effect of ultrasound on the human body is confirmed, in particular, by the fact that when a number of joints are affected, it is often enough to limit the therapy to one of them, since there is a parallel improvement in the remaining joints. Positive results were obtained in the treatment of spondylitis, ankylosing spondylitis, varicose, flaccid granulating and trophic ulcers, and obliterating endarteritis using ultrasound.
There are separate indications of the positive use of ultrasound in bronchial asthma, duodenal and gastric ulcers, bronchiectasis, pulmonary emphysema, Meniere's disease and otosclerosis. There are also observations that indicate that preliminary skin scoring enhances the effectiveness of X-ray irradiation.