The influence of ultrasound on humans. The concept of ultrasound therapy, methodology, indications, restrictions on use

The intensity of ultrasound used for medical diagnostics and physiotherapy, significantly lower than its intensity in industrial settings. But still, does ultrasound cause harm to the body when performed? medical examinations? The doses of ultrasound received by patients during diagnostic studies have virtually no effect on the patient’s body, while therapeutic doses give healing effect. Focused and directed high intensity ultrasound causes local destruction individual areas living tissue. This type of ultrasound is used during surgical interventions.

In order to study the effects and harm of ultrasound on the body, numerous studies have been conducted on animals. The results of these studies showed that repeated exposure to ultrasound with an intensity of 1-3 W/cm2. caused disturbances in cells nerve tissue, liver, kidneys and other organs. At an intensity of 5-10 W/cm2. pathological changes also appeared in muscle fibers and blood cells, and increasing the dose to 60 W/cm2. caused paralysis in “sounded” rats. However, it was found that ultrasound doses are less than 0.05 W/cm2. practically indifferent to the body. They do not have any noticeable effect on him.

Standard diagnostic ultrasound equipment uses ultrasound with an intensity from 0.001 to 0.05 W/cm2, which is safe for the body. In addition, most diagnostic medical ultrasound machines operate in pulsed mode; They do not generate ultrasound for the entire duration of the examination, but for only one thousandth of every second. The remaining 999 thousandths are allocated for receiving echo signals and analyzing them. It is easy to calculate that with a half-hour echocardiographic study, the total “pure” time of ultrasound irradiation will be no more than 2 s. But this dose does not fall on one place, since the sensor moves from one position to another during the study. All this together guarantees complete safety of pulsed ultrasound diagnostics for the patient.

When using diagnostic ultrasound devices that operate not in pulsed mode, but in continuous mode, the body receives a slightly larger dose of ultrasound. But since the intensity of ultrasonic irradiation in them does not exceed 0.015 W/cm2, this dose is also safe for the health of the examined persons.

In cardiology today it has already been carried out great amount ultrasonic diagnostic studies, however, nowhere - neither in our country nor abroad - was it ever mentioned adverse consequences related to the use of ultrasound for diagnosis. According to recent reports, ultrasound may even be beneficial for the heart in some cases. Canadian scientists have discovered that after intensive physical activity Under the influence of ultrasound, the rhythm of cardiac activity is more quickly normalized in both patients and healthy people. Researchers explain this fact by the fact that ultrasonic vibrations massage the membranes and internal partitions of the heart muscle fibers. At the same time, the transport of oxygen and calcium ions into the myocardial cells is enhanced, which contributes to the normalization of heart rhythm.

The question of the dangers of ultrasound was of particular concern to obstetricians, since even a small harmful effects the fruit can have a very dangerous consequences. The results of experiments with repeated irradiation of pregnant animals (rats, mice) with diagnostic doses of ultrasound are clear: sounding has no effect harmful influence neither on the fetus nor on the maternal body.

Diagnostic ultrasound has become firmly established in obstetric practice. Observations were carried out on hundreds of children whose mothers different periods pregnancies were exposed to ultrasound, the long-term results of this exposure were analyzed, but doctors did not note any abnormalities during pregnancy, childbirth or the development of children that could be associated with the diagnostic ultrasound examination that took place.

With regard to the doses used in ultrasound physiotherapy, there are individual reports of an increase in the number of developmental anomalies in fetuses in animal experiments under the influence of prolonged exposure to ultrasound with an intensity of 0.125-0.50 W/cm2. Therefore, it is not recommended to prescribe ultrasound treatment procedures during pregnancy.

Ultrasound therapy usually uses ultrasound at a relatively safe intensity - from 0.05 to 0.8 W/cm2. High powers - from 0.8 to 1.2 W/cm2. used very rarely. The time of therapeutic scoring does not exceed 10-15 minutes. The course of treatment includes 6 to 14 procedures, performed daily or every other day. A repeat course is prescribed no earlier than two months after the end of the previous one. Power physiotherapy ultrasonic devices checked monthly using special reference devices (ultrasound power meters). Numerous experimental studies And clinical observations they are convinced that if the technique and regimen, dose and time of irradiation are followed, ultrasound physiotherapy does not give any complications.

In surgery, destructive ultrasound is used. But surgical ultrasound cannot be called dangerous, since its destructive effect is short-term and strictly localized, and the surrounding tissues remain undamaged. If we add such advantages of using an “ultrasonic scalpel” as low pain, good stopping of capillary bleeding, fast healing surgical wound, it becomes clear why ultrasound, along with laser, is successfully used in facial plastic surgery, eye surgery, brain surgery, crossing additional cardiac pathways and many other complex surgical interventions.

We all know that the heart works rhythmically. Even short-term disturbances in heart rhythm - “interruptions”, “palpitations” - are a sign of serious trouble in the body. The main working mechanism that controls both the rhythm and orderliness of contractions of the heart muscle is inherent in it itself. This is the so-called conduction system of the heart, operating on the basis of the reflex principle. It consists of atypical muscle tissue, nerve cells and fibers. With changes in the conduction system of the heart, heart rhythm disturbances develop. Heartbeat In some cases it can sharply slow down (bradycardia), in others it can accelerate excessively (tachycardia), and sometimes it can become completely disorganized. In some cases, the “culprits” of tachycardia may be additional pathways remaining in the heart as a result of developmental abnormalities. Several types of operations have been developed to interrupt them. Israeli surgeons from transplantology and artificial organs used ultrasound during operations of destruction (destruction) of additional conduction pathways. After the operation performed with the help of an ultrasonic destructor, the patients achieved normal sinus rhythm.

Table of contents
Page
Introduction…………………………………………………………….…..………..3
1. “Ultrasound” and its application in medicine………………………………………………………4
1.1. How does “ultrasound” affect the human body……………………………….5
1.2. Consequences of ultrasound exposure on the body………………………8
2. Warnings of the harmful effects of ultrasound………………………………...9
2.1. Contraindications for employment………………………………….11
Conclusion……………………………………………………………… ……………………………12
Bibliography…………………………………………………. .13

Introduction

The scope of application of ultrasound today is unusually wide. This includes navigation, industry, medicine and much more. Is ultrasound harmful to humans? Judging by the fact that in medicine ultrasound is used not only for diagnosis, but also for treatment, we can answer that no, it is not harmful. But this is not entirely accurate. As in many other things, it is important to know the limit here; in our case, the measure is volume. Ultrasound, like the sounds we hear, has volume. Doctors consider a safe volume of 80-90 dB; ultrasound volume above 120 dB with prolonged exposure has a negative effect on human health.

Technological processes: cleaning and degreasing of parts, mechanical restoration hard and brittle materials, welding, soldering, tinning, electrolytic processes, acceleration of chemical reactions, etc. use ultrasonic vibrations of low frequency (LF) - from 18 to 30 kHz and high power - up to 6-7 W/cm 2. The most common ultrasound sources are piezoelectric and magnetic transducers. In addition, in industrial conditions, LF ultrasound is often generated during aerodynamic processes: the operation of jet engines, gas turbines, powerful air engines, etc.

1. “Ultrasound” and its application in medicine

Ultrasound– these are mechanical vibrations of an elastic medium, propagating in it in the form of variable compression and rarefaction; with a frequency above 16-20 kHz, not perceptible to the human ear.
As the frequency of ultrasonic vibrations increases, their absorption by the environment increases and the depth of penetration into human tissue decreases. Absorption of ultrasound is accompanied by heating of the medium. The passage of ultrasound in a liquid is accompanied by the effect of cavitation. The ultrasound generation mode can be continuous or pulsed.

Ultrasound has become widespread in medicine for the treatment of diseases of the spine, joints, peripheral nervous system, as well as for performing surgical operations and diagnosing diseases. American scientists have developed an effective method for removing brain tumors (2002) that are not amenable to conventional surgical treatment. It is based on the principle used in cataract removal - crushing the pathological formation with focused ultrasound. For the first time, a device has been developed that can create given point ultrasonic vibrations of the required intensity without damaging surrounding tissues. Ultrasound sources are located on the patient's skull and emit relatively weak vibrations. The computer calculates the direction and intensity of the ultrasound pulses so that they merge with each other only in the tumor and destroy tissue.

In addition, doctors have learned to re-grow lost teeth using ultrasound (2006). Low-intensity pulsating ultrasound stimulates the regrowth of knocked out and lost teeth, researchers from Canada's University of Alberta have discovered. Doctors have developed a special technology - a miniature “system on a chip” that ensures the healing of dental tissue. Thanks to the wireless design of the ultrasound transducer, a microscopic device equipped with biologically compatible materials is placed in the patient’s mouth without causing discomfort.
Diagnostic ultrasound has been intensively used for three decades during pregnancy and for diseases of individual organs. Ultrasound, encountering an obstacle in the form of human or fetal organs, determines their presence and size.

1.1. How does ultrasound affect the human body?

In addition to the general effect on the body of those working through the air, LF ultrasound has a local effect upon contact with workpieces and environments in which ultrasonic vibrations are excited. Depending on the type of equipment, the area of ​​greatest impact of ultrasound is the hands. Local action can be permanent (holding the tool against the workpiece during tinning, soldering) or temporary (loading parts into baths, welding, etc.).

Exposure to powerful installations (6-7 W/cm2) is dangerous, because it can lead to damage to the peripheral nervous and vascular apparatus in places of contact (vegetative polyneuritis, cuts in the fingers, hands and forearm). Contact exposure to ultrasound most often occurs during loading and unloading of parts from ultrasonic baths. A three-minute immersion of fingers in bath water with a converter power of 1.5 kW causes a tingling sensation, sometimes itching, and after 5 minutes. after the cessation of the ultrasound, a feeling of cold and numbness of the fingers is noted. Vibration sensitivity sharply decreases, pain sensitivity in different persons in this case it can be either increased or decreased. Short-term systematic contact with the sounded environment lasting 20-30 s or more in such installations can already lead to the development of the phenomena of vegetative polyneuritis.

Particular attention should be paid diagnostic ultrasound. Kruskal's review of Diagnostic Imaging in Pregnancy (2000) noted that ultrasound waves have the potential to cause damage to biological tissues due to heating and cavitation. However, there is no documented evidence of the biological effects of ultrasound. The Canadian Society of Obstetricians and Gynecologists noted in a 1999 statement that there is no scientific evidence that diagnostic ultrasound is harmful to the developing fetus. It has previously been suggested that ultrasound exposure may be associated with low birth weight, dyslexia, increased incidence of leukemia, solid tumors, delayed learning to read and write. The risk of ultrasound examination consists mainly of possible overdiagnosis or the possibility of missed pathology.

Permissible sound pressure levels of ultrasonic installations should be taken in accordance with “Sanitary norms and rules for working on industrial ultrasonic installations” No. 1733-77, GOST 12. 1. 001-89, SanPiN 2. 2. 2/2. 1. 8. 582, which are given for 1/3 octave bands in the frequency range 1.25-100 kHz and amount to 80 - 110 dB. At contact action The ultrasound level should not exceed 110 dB. GOST provides for changes in the ultrasonic maximum level with a total reduction in the time of its exposure (by 6 dB with an exposure time of 1... 4 hours per shift and 24 dB with an exposure time of 1... 5 minutes).

Under the influence of ultrasound, the permeability of cell membranes for various biologically active substances involved in metabolic processes, the speed of enzymatic processes, the electrical activity of tissue cells and some other processes change. In tissues under the influence of ultrasound, metabolic processes are activated, the content of nucleic acids increases and the processes of oxygen absorption by tissues are stimulated.

Under the influence of ultrasound, it increases the permeability of blood vessels, therefore, in acute inflammatory processes with pronounced edema tissue, the disease may worsen. But in subacute and chronic inflammatory processes that are not accompanied by edema, improvement occurs, since ultrasound promotes resorption of the process. A pronounced antispasmodic (relief of smooth muscle spasms) internal organs and walls blood vessels) influence of ultrasound.

Ultrasound promotes less rough scarring of wounds and inflammatory processes, and also leads to the softening of already formed scar tissue, which makes any scars less rough and noticeable after ultrasound treatment. Therefore, phonophoresis is used in the treatment of consequences various injuries, and adhesive processes after surgical interventions and inflammatory diseases.

Small doses of ultrasound have a stimulating effect on tissue restoration processes, while large doses inhibit these processes. Ultrasound inhibits the conduction of pain impulses in nerve cells and nerve fibers, which makes it possible to use it for various pain syndromes.

Ultrasound has a stimulating effect on the endocrine system: the content of insulin and glucocorticoids in the blood increases.

Under the influence of ultrasound, both local tissue changes occur (activation of local metabolic processes, improvement of blood circulation in small blood vessels, restoration processes), and complex reactions of the whole organism, as a result of which an increase in protective forces body and recovery processes in the body as a whole.

1.2. Consequences of ultrasound exposure on the body

Functional changes in the central and peripheral nervous system, cardiovascular system, auditory and vestibular analyzers, endocrine and humoral deviations from the norm. Headaches with predominant localization in the frontonasal orbital and temporal regions, excessive fatigue. Feeling of pressure in the ears, unsteadiness of gait, dizziness; sleep disturbance (drowsiness during the day); irritability, hyperacusis, hyperosmia, fear of bright light, increased pain excitability thresholds; under conditions of exposure to intense ultrasound accompanied by noise - insufficiency of vascular tone (lowering blood pressure, hypotension), disinhibition of skin-vascular reflexes in combination with a strong vasomotor reaction; general cerebral disorders; vegetative polyneuritis of the hands (less often legs) varying degrees(pastyness, acrocyanosis of the fingers, thermal asymmetry, sensitivity disorder like gloves or socks); increased body and skin temperature, decreased blood sugar, eosinophilia. The severity of pathological changes depends on the intensity and duration of ultrasound; contact with a sound environment and the presence of noise in the spectrum also worsen health.

Compared to HF noise, ultrasound has a noticeably weaker effect on auditory function, but causes more pronounced deviations from the norm in vestibular function, pain sensitivity and thermoregulation. Intense HF ultrasound upon contact with the surface of the body causes essentially the same disturbances as LF.

2. Warnings of the harmful effects of ultrasound

The prevention of the harmful effects of ultrasound is based on technological measures: the creation of automatic ultrasonic equipment (for washing containers, cleaning parts), remote-controlled installations; transition to the use of low-power equipment. In this case, the intensity of ultrasound and noise is reduced by 20-40 dB (for example, during ultrasonic cleaning of parts, soldering, drilling, etc.).

When designing ultrasonic installations, it is advisable to choose operating frequencies that are as far as possible from the audible frequency range (not lower than 22 kHz) in order to avoid the effects of pronounced HF noise.

Ultrasonic installations with noise and ultrasound levels exceeding the standards should be equipped with sound-insulating devices: casings, screens made of sheet steel or duralumin. Covered with sound-absorbing materials: roofing felt, technical rubber, plastic, anti-vibration, anti-noise mastic. Soundproofing covers of ultrasonic installations must be insulated from the floor with rubber gaskets and have no cracks or holes.
etc.................

Ultrasound diagnostics is used in many cases. An examination in this way allows you to get results without serious interventions into the work of the body. Is ultrasound harmful to humans?

What is ultrasound

Ultrasound is a vibration sound waves, maximum value is 20 kHz. This value is not discernible for hearing aid.

Ultrasound is used in medicine. With its help, examinations of internal organs are carried out without any mechanical intervention. The image is displayed on the screen in black and white.

After decoding, a diagnosis is established. An examination is prescribed if there is a suspicion of inflammatory processes inside the body, a suitable treatment is selected.

At correct use ultrasound diagnostics does not harm health. However, repeated repetitions of the procedure, prolonged and intense exposure have an adverse effect on the body.

Ultrasound is used not only for medical examinations. It is used to clean teeth from tartar.

Waves are used in industry - for cleaning objects from various impurities, for welding, for operating engines and turbines. IN agriculture Ultrasound helps get rid of rodents and insects.

Many people purchase air humidifiers for their homes. The devices are also ultrasonic and cause concern among consumers. However, it is quite difficult to suffer from a humidifier. All devices are thoroughly tested and proven to not cause serious harm to the body.

Ultrasound is used in cosmetology to get rid of wrinkles on the skin. Such a lift does not require surgical intervention. A three-level focal ultrasound effect is performed on the facial muscles. One side is processed first, then the other. The duration of the Haifa lift is sixty minutes, depending on the condition of the client’s skin. The result becomes noticeable after five months.

The effect of ultrasound on the body

What effect does ultrasound have on the body in adults and children, what happens to internal organs during the procedure? Proper use does not have any effect negative influence per person. The harm of ultrasound depends on different indicators– power and frequency. In each case, the most appropriate values ​​are selected.

Long-term exposure to ultrasonic waves disrupts the functioning of organs, develops inflammatory processes, and leads to necrosis of living tissues.

Even with a single exposure to powerful waves, disturbances occur at the cellular level.

In contrast, ultrasound examinations do not lead to accumulation harmful substances in organism. Therefore, the procedure is allowed for pregnant women and children.

Is ultrasound harmful to personnel? medical institution? People working with such research apparatus must be attentive and careful. Means have been created to protect against negative impact device, you must follow the rules for working with the device.

Harm and benefits of ultrasound for humans

How dangerous is ultrasound to health? During a standard examination, there is no accumulation of radiation in the body. When the device stops operating, the ultrasonic effect stops.

Prolonged and regular exposure to radiation negatively affects health. People working with ultrasound are susceptible to frequent illnesses. The central nervous system is primarily affected. In case of disorders in the functioning of the central nervous system, failures of various life processes are diagnosed.

Personnel associated with ultrasonic devices have experienced symptoms of negative wave effects.

Symptoms:

• Constant weakness, increased fatigue;
• Pain in the head;
• Nervousness, aggression;
• Sleep disturbance;
• Increased sensitivity to sounds;
• Pallor skin, in some cases redness;
• Memory problems, poor concentration;
• Cold extremities;
• Loss of consciousness;

Staff may experience work disruptions digestive system, kidneys, thyroid and gonads.

Vegetative sensitive or vegetative pleurisy is often diagnosed. For this state the presence of certain signs is characteristic.

Signs:

1. Loss of hand sensitivity;
2. Blue discoloration of the upper layer of the epidermis;
3. Increased peeling of the skin;
4. Swelling;

The development of cardiac and vascular diseases. Possible changes in blood counts, decreased hemoglobin, lack of minerals. There are three stages of the appearance of changes in the body.

Stages:

• Initial. There are minor changes in the functioning of the nervous system and internal organs.
• Moderate. Diencephalic disorder is of mild degree, symptoms manifest themselves more intensely.
• Expressed. At this stage, disorders of the nervous system are clearly visible.

However, moderate use of ultrasound has beneficial properties. The phenomenon is used in physical therapy and other medical procedures.

Beneficial features:

1. Healing of wounds and injuries occurs faster;
2. Scar tissue dissolves;
3. Reduces pain in bone tissue, muscles;
4. Reduced skin sensitivity to medications;
5. Cells of harmful bacteria are destroyed;

Ultrasound examination is characterized by a low price, but complete information about the condition and functioning of internal organs. It is often prescribed during pregnancy and preparation for surgical interventions. During pregnancy, examination allows you to determine the sex of the child, its development in different time, no deviations.

Is ultrasonic teeth cleaning harmful?

Is it useful to brush your teeth with ultrasound? Brushing your teeth this way helps get rid of solid deposits on enamel. For the procedure, a medical instrument is used - a scaler. The patient does not feel painful sensations and discomfort.

Using the device, it is possible to remove stones on the enamel and clean the space under the gums. Ultrasound removes pathogenic bacteria, lightens the enamel to a natural shade, allows you to rinse the root and periodontal canals, and assess the condition of the gum tissue. When used correctly, it does not harm teeth and enamel.

The main disadvantages of the procedure are the risk of soft tissue damage. In some cases, it is necessary to curettage periodontal pockets, which leads to bleeding gums.

The quality of cleaning depends on the professionalism of the dentist and the type of device used. Using old-style devices increases the risk of soft tissue injuries.

Ultrasound can be useful and harmful. An experienced physician will conduct the examination without harm to the patient. However, people working with ultrasonic devices need to be careful and use protective equipment.

Video: ultrasonic teeth cleaning (benefits or harm?)

An unusual sensation that is perceived by our ear as sound is an action various kinds vibrations of the so-called dense medium, in particular air, on the hearing aid.

But not all vibrations that occur in the medium cause the sensation of sound. The lowest frequency limits at which the hearing aid can recognize sound is 20 hertz.

Most high threshold is about 16 or 20 thousand hertz. Determining these boundaries depends on individual variation.

Ultrasound when exposed to human body , is capable of being transformed into thermal energy, which causes a feeling of warmth when exposed to it. It causes a so-called micro massage of tissue (its compression and stretching), which has a beneficial effect on blood circulation, which subsequently improves tissue functions.

When exposed to it are improving metabolic processes body, and ultrasound also provides some neuro-reflex effects.

Changes after exposure to ultrasound are noted not only in the place where the ultrasound was applied, but also in other parts of the body. With prolonged exposure, ultrasound can lead to some tissue destruction.

Experts believe that its destructive effect is associated with the so-called cavitation effect. This effect causes cavities to form in the fluid, leading to cell death.

Such cavities were identified in experiments performed on animals. The results show that receipt bubbles were formed in the intercellular space.

Ultrasound can kill many types of microorganisms. Capable of inactivating some types of viruses. Negatively affects the structure of proteins, disrupting it and ultimately destroying it completely. When milk is exposed to ultrasound, its destructive properties completely destroy its vitamin C content.

In medicine, ultrasound is used to sound the blood, which leads to an increase in its clotting properties. We can say that ultrasound suffocates the cells of the body. Because of it, the cell cannot breathe normally and carry out its metabolic processes.

Experiments on animals show that intense exposure to ultrasound leads to severe pain, baldness, some burns, the cornea and lens become clouded, serious violations biochemical nature, hemolysis, and exposure high frequencies, death occurs as a result of minor hemorrhages in various organs body

Experimental data show that Ultrasound can seriously affect the sensitivity of the hearing aid. Experts believe that the large percentage of the United States population with hearing loss is due to exposure to sound systems that are widespread throughout the country.

People who have been exposed to ultrasound for a long time feel some drowsiness and fatigue.

It is contraindicated to voice a growing body, genitals, or heart. This can cause extreme Negative consequences associated with cardiovascular disorders. The use of ultrasound is also contraindicated in certain diseases, as well as during pregnancy.

Due to the increasing use of ultrasound, some people are unwittingly exposed to it. To prevent negative changes in the body, you should undergo examinations and, in the presence of ultrasound exposure, perform prophylaxis to neutralize further changes

A pressing question to this day is: is ultrasound harmful to humans? However, it is easier to prove its benefits and vital necessity. Diagnosis and examination of internal organs is currently almost impossible to imagine without ultrasound examination, or ultrasound. Ultrasound is much more effective than many other examinations, because it is possible to visually assess both the condition of the organ being examined and the tissues surrounding it, and nearby organs Same.

One of the types of ultrasound is Dopplerography - the study of blood vessels and blood flow speed. This method allows you to identify the reasons various diseases: from urological to neurological.

Ultrasound diagnostics is necessary for examining pregnant women; thanks to ultrasound, the presence is confirmed, the sex of the child, the size of the fetus are determined, various pathologies. Modern high-precision devices provide the possibility of ultrasound examination in 3D and 4D formats. In this way, you can see the baby from all sides even before his birth, and also assess the blood flow in the uterus. Using this method, you can get your first child and even record on DVD how the baby in the womb reacts to the mother’s voice, to a touch on the stomach.

Ultrasound has many advantages over other studies. This is painlessness, ease of examination, non-invasiveness (i.e. the examination does not require penetration into the body), in most cases, ultrasound does not require preliminary preparation. Modern ultrasound equipment is equipped with color printers, which allows you to monitor the development of diseases or the effectiveness of treatment.

One of the disadvantages of ultrasound is the low image resolution compared to MRI, but in most cases this quality is enough to diagnose a particular disease, or its absence.

Other possibilities of ultrasound are now used in medicine and cosmetology. One type of physiotherapeutic treatment is ultrasound therapy. Ultrasound has a pronounced anti-inflammatory, analgesic, and tonic effect. It stimulates blood circulation, thereby supplying tissue. Ultrasound therapy is most often used for diseases of the ears, nose, throat and is effectively treated gynecological diseases, cornea of ​​the eye, ultrasound can crush stones in the kidneys or bladder.

With the help of ultrasonic massage you can activate lymphatic drainage and cellular metabolism. In beauty salons, ultrasonic facial cleansing and peelings are carried out; they not only cleanse pores of dirt, but also increase skin elasticity. The contact between the ultrasound device and the skin is conducted by conductive gels, lotions or oil solutions.