The epic of the construction of the Baikal-Amur railway line and the development of the adjacent territories, the solution of the medical and biological problems associated with them has not sunk into oblivion. It is in scientific works, in the memory of the participants, in the accumulated huge

experience of large-scale complex research, the results of which, often of general biological significance, can be applied to any regions with extreme conditions of human existence.

RESEARCHES OF EMPLOYEES OF FACULTY OF HOSPITAL THERAPY ISMI AND THE ACADEMIC GROUP K.R. SEDOVS IN THE ZONE OF CONSTRUCTION OF THE BAIKALAMUR RAILWAY

Y.V. Zobnin (Irkutsk State Medical University)

The historical sketch of scientific-practical researches and other actions under the decision of medical and biologic problems of region of construction of a Baikal-Amur trunk-railway and new economic development of the adjoining territories which have been carried out by employees of faculty of hospital therapy of Irkutsk state medical institute and the academic group under the direction of the full member of Academy of Medical Sciences of the USSR KR Sedova is submitted.

© E. V. SHEVCHENKO, H. A. Khlopenko - 2006

EFFECTS OF ULTRASOUND ON THE BODY

E.V. Shevchenko, H.A. Khlopenko

(Irkutsk State Medical University, Rector - Doctor of Medical Sciences, Prof. I.V. Malov, Department of Medical and

biological physics, head. - Doctor of Biological Sciences, prof. E.V. Shevchenko)

Summary. It is shown that the main characteristics of ultrasound (frequency, intensity, duration of exposure) largely determine the features of its propagation in the environment and biological tissues. When ultrasound propagates in biological tissues, a number of effects (mechanical, thermal, physicochemical) are manifested, which leads to some deviations from the physical laws of its propagation in a substance, the nature of which must be taken into account when carrying out diagnostic and therapeutic measures. Keywords. Ultrasound, characteristics, biological tissue, diagnostics._

Modern clinical medicine It is inconceivable without powerful diagnostic support, without which it is fundamentally impossible to earn and timely adjust the plan of adequate treatment. This provision is based on the use of high technologies of radiation diagnostics, which allows visualizing normal and pathological tissues of the human body using various physical agents. The composition of radiation diagnostics now includes X-ray diagnostics, including X-ray computed tomography, radionuclide diagnostics, ultrasound examinations (US), magnetic resonance imaging, thermography and some other less common diagnostic technologies.

Ultrasound is an important diagnostic tool. Ultrasound diagnostics allows, without disturbing the skin and without much interference in the physiological processes of the body, to study the position, shape, size, surface condition and internal structure of all human organs, as well as assess their functional state.

Ultrasound is a mechanical vibration of an elastic medium, which occupies a region above 16000 Hz. The upper limit of the ultrasonic vibration spectrum has not been established. In medicine, ultrasound of a relatively high frequency of 800 ^ 3000 kHz is used. For semi-

in the field of ulygrazvuk, special devices are currently being used, in which piezoelectric, magnetostrictive, electrodynamic, aerodynamic and hydrodynamic effects are used.

Frequency response and wavelength largely determine the features of the propagation of vibrations in the environment. If low-frequency ultrasound has the ability to propagate in the air, then high-frequency ultrasound practically does not propagate in the air due to strong absorption. At a short wavelength, ultrasound can be focused and guided by a linear beam. With decreasing wavelength, the diffraction ability of the wave decreases, which creates favorable conditions for screening.

Oscillatory movements of matter particles occurring in the ultrasonic wave are characterized by a very small amplitude of displacement and extremely large accelerations. So, at a frequency of 880 kHz and an intensity of 2 W / cm2, body tissue particles vibrate with an amplitude of 3.5-10-6 cm.The maximum acceleration in this case reaches 90-104 cm / s2, which exceeds the gravitational acceleration of bodies by almost 100 thousand times. The velocities of the propagation of ultrasound in the tissues of humans and animals ranges from 1490 to 1610 m / s, i.e., almost does not differ from the velocity of propagation of ultrasound in

water. The temperature of the medium has a significant effect on the speed of ultrasound. When the air temperature rises by 1 °, the speed increases by 0.5 m / s. At an air temperature of 0 °, the speed of sound and ultrasound is 331.5 m / s, and at a temperature of + 18 ° C, it increases to 342 m / s. An increase in water temperature by 1 ° leads to an increase in speed by 2.5 m / s.

In addition to the specified parameters (frequency, wavelength and speed), ultrasound is characterized by intensity. In medical practice, according to the intensity, ultrasonic vibrations are divided into three ranges: up to 1.5 W / cm2 - small; 1.5 3 W / cm2 - average; 3 ^ 10 W / cm2 - high intensity.

When ultrasound passes from one medium, part of the energy passes into the second medium, and part is reflected. Reflection depends on the acoustic impedance of the media. The more the values \u200b\u200bof the acoustic resistance of the two media differ, the greater the reflection of ultrasonic waves at the interface. For example, the acoustic resistance of air is 41 g-s / cm2, and of water 15-104 g-s / cm2. Due to the large difference in these values, the reflection coefficient at the interface is 0.9993, i.e. about 0.1% of the energy passes from air to water and back. Ultrasound propagates from metal to air and vice versa just as badly.

It is known that ultrasonic vibrations propagate well from water into biological tissues and, conversely, pass poorly from air into tissues. Thus, it was found that the absorption coefficient of ultrasound propagating from air to skin is the same as at the air-water interface.

But at the same time, one cannot conclude that ultrasound does not penetrate into tissues and is almost completely reflected from the surface of the body, since it is necessary to take into account the structure of the skin, without ignoring the fact that it consists of tissues of different moisture content. The superficial layer of the skin (epidermis) contains little moisture and cannot be identified from this point of view with internal organs, muscle tissue, and even more so with water. It is also necessary to remember the small thickness of the epidermis. It is possible that for this reason, it cannot be a serious obstacle to the propagation of ultrasound into the deeper layers of the skin. The absorption of ultrasound by human tissues was studied in order to clarify its possible effect on the body. However, based on the magnitude of the absorption coefficient alone, biological effect... Obviously, one should also take into account the reflection phenomena occurring in the tissues, which can lead to an increase in the biological effect.

The foregoing indicates the need for an analytical approach to assessing the relative values \u200b\u200bestablished by physicists. When solving hygienic issues, it is necessary to proceed, first of all, from their biological significance.

When ultrasonic vibrations propagate in various media, their intensity weakens in inverse proportion to the square of the distance from the source. The loss of energy occurs due to the absorption of ultrasound by the media in which it propagates. The absorption is due to the viscosity and thermal conductivity of the medium. It was found that the absorption of ultrasound in air is about 2000 times greater than in water. By-

absorption also depends on the frequency of ultrasonic vibrations and increases in proportion to the square of the frequency. Therefore, the attenuation of ultrasonic waves increases rapidly with increasing frequency.

It should be noted that the absorption of ultrasound in biological tissues does not obey general physical laws at all. In biological tissues, there is not a quadratic, but a linear dependence of absorption on frequency. This is due to the great heterogeneity of the tissues. The heterogeneity of biological tissues is also due to the different degrees of absorption of ultrasound. For example, absorption is lowest in fat and nearly double in muscle. The gray matter of the brain absorbs 2 times more ultrasound than the white matter. Absorbs little ultrasonic energy cerebrospinal fluid... The greatest absorption is observed in bone tissue.

During the propagation of ultrasound in a medium, a number of effects are manifested, the main ones being: mechanical, thermal, and physicochemical. The passage of ultrasound in media is accompanied by their heating due to the conversion of acoustic energy into thermal energy as a result of the absorption of ultrasound. In addition, the generation of heat is due to physical phenomena that cause the so-called effect of boundary surfaces. Its essence is to enhance the action of ultrasound at the interface between two media, which leads to an increase in the thermal effect several times. This is due to the reflection of vibrations from the boundary surfaces: the greater the reflection, the more pronounced their effect, i.e. with an increase in the surface reflecting vibrations, the thermal effect increases. When performing ultrasound therapy with a tight fit of the ultrasound source to the skin, the patient does not experience any unpleasant sensations. But if there is a small layer of air between the skin and the head of the emitter, a burning sensation appears. The enhancement of the thermal effect is due to the intense reflection of ultrasonic vibrations at the skin-air interface due to the large difference in their acoustic impedance.

The mechanical effect, in turn, is due to the very nature of ultrasound, which is a wave motion of gaseous, liquid and solid media, and is associated with alternating acoustic pressure during compression and extension of the medium and forces developing due to large accelerations of particles. This determines the grinding and dispersing action of ultrasound.

It is known that the excitation of ultrasonic vibrations in a liquid is accompanied by cavitation. In a liquid, during the propagation of elastic waves, phases of compression and depression appear sequentially. In the vacuum phase, breaks or cavities are formed in individual sections of the liquid, which are filled with liquid vapors or gases dissolved in it. Subsequent compression leads to the collapse of the formed bubbles. Before slamming, a lot of pressure is created in them. Therefore, at the moment the bubbles disappear, powerful hydraulic shocks occur, which have a great destructive force. In addition to the release of mechanical energy, the formation of cavitation cavities is accompanied by the appearance

electric charges on boundary surfaces, causing luminescent glow and ionization of water molecules, decaying into free hydroxyl radicals and atomic hydrogen. Chemically, the decay products of ionized water molecules are extremely active. It is their great activity that determines a number of general biological effects manifested under the influence of ultrasound. In particular, this is associated with its oxidizing effect; disintegration of proteins in an ultrasonic field; depolymerization of protein compounds, inactivation of enzymes, acceleration of chemical reactions.

Investigations of the biological effect of high-frequency ultrasound on animals and humans were mainly caused by the needs of practical medicine - the need to study, develop and establish the optimal therapeutic doses of high-frequency ultrasound applied by the contact method. The importance of this problem was also due to the fact that since the end of the 40s, reports began to arrive about various complications associated with an overdose of high-frequency ultrasound in medical practice. At present, the intensity of the applied therapeutic ultrasound at frequencies from 800 kHz to 1 ^ 1.5 MHz is significantly reduced: instead of 2 ^ 4 W / cm2, 0.2 ^ 0.4 W / cm2 is most often used. In the case of diagnostics, the ultrasound parameters remain still high: the frequency can reach from 800 kHz to 20 MHz, the intensity can vary between 0.01 ^ 0.1 W / cm2 and 10 ^ 20 W / cm2, and sometimes even more.

The study of the biological effect of contact high-frequency ultrasound on various systems of the whole organism showed that the most sensitive to it is the central and peripheral nervous system: first of all, the brain-hypothalamus and the reticular formation of the trunk, cerebral cortex, central and peripheral vegetative structures and then peripheral nerves ... Cardiovascular and respiratory functions primarily suffer as a result of exposure to ultrasound on the corresponding hypothalamic and brainstem centers.

Experimental studies have shown 3 characteristic stages of the biological action of high-frequency ultrasound on warm-blooded animals. Intense irradiation of the brain at a frequency of 400 kHz consistently caused: 1) excitement, 2) inhibition, and 3) paralysis of the respiratory, and then the cardiovascular centers. On records blood pressure and respiration, respectively: initial excitement, a subsequent increase in pressure to critical values \u200b\u200band respiratory paralysis, as is observed in shock. The whole clinical picture in general, they are found to be very close to concussion, which was confirmed by histological processing of these materials. Researchers interpret these changes in the brain as traumatic, caused by the mechanical action of ultrasound, while wedge-shaped foci of necrosis are considered a characteristic distribution of radiant ultrasonic energy. Ultrasound exposure of different intensities to different areas of the head led to pronounced trophic changes (weight loss, non-healing ulcers, hair loss), deep asthenia, endocrine disorders, metabolic

disorders, to a change in the composition of peripheral blood - leukocytosis or leukopenia, a change in the hemolytic resistance of erythrocytes, etc. This is due to the reflex action of high-frequency ultrasound on the autonomic centers of the brain and, first of all, the hypothalamic region.

Ultrasonic vibrations change the structure of cell membranes, increase their permeability, stimulate the processes of hydrolysis, glycolysis, and the activity of biocatalysts. They increase the permeability of the skin, increase the activity of cholinesterase by almost 2 times. The participation of the cerebral cortex in the functional restructuring of the body's activity, which occurs under the influence of ultrasonic irradiation, has been proved. Experiments have shown that under the influence of ultrasonic vibrations of different intensities, directional changes in the biopotentials of the cerebral cortex occur, while weak and single sounding is accompanied by an increase in the biopotentials of the cortex, repeated or intense exposure to ultrasound leads to a decrease in them, up to complete bioelectric "silence". So, depending on the intensity and duration of exposure, ultrasounds have a stimulating, activating effect, or they inhibit, inhibit and suppress biological processes, physiological reactions of the body.

When dubbing different departments spinal cord and peripheral nerve trunks, the same patterns are noted as in the sounding of the brain. The pathogenesis of ultrasound changes can be explained by mechanical vibrations - vibration microtraumatization, leading to the phenomena of spinal concussion.

With regard to peripheral nerves, the same regularities were established for the effect of ultrasound of different intensities: ultrasounds of low and medium power increase excitability and accelerate conduction nerve impulse; with an increase in the intensity and duration of sounding, the inhibition of nerve excitability increases until a complete block appears; swelling of nerve fibers, their tortuosity, vacuolization and decay are pathohistologically determined.

The practice of the therapeutic use of high-frequency ultrasound also revealed the possibility of its adverse effect on the peripheral parts of the nervous system. With the therapeutic effect of high-frequency ultrasound 1.5 W / cm2, analgesia was observed in the zone of nerve innervation below the site of sounding.

In a number of observations, data on diseases of the peripheral nerves of the active arm in persons who dispense medical procedures are given. Releasing ultrasound procedures for hundreds of patients, experts note pain, paresthesias and weakness of the right hand; after switching to the left hand, similar phenomena occur in the left hand.

Of great interest are functional and morphological changes in various tissues and organs, arising, according to the conclusion of most authors, from the effect of ultrasound on the central nervous system. In this regard, skin analyzers and the autonomic nervous system, which is especially richly represented in the periphery, play an essential role. The skin is a kind of antenna of the autonomic nervous system, re-

giving ultrasound stimulation on the path of skin-visceral reflexes. In addition, ultrasound stimulation, falling on the receptor apparatus of the skin, is transmitted in all directions to the peripheral and central formations of the sympathetic and parasympathetic nervous systems, to all levels of the spinal cord and brain, both through specific and non-specific pathways. Based on experimental and clinical research many authors have identified regular changes in cardiovascular activity.

The study of the vascular reactions of the body to the effects of ultrasound made it possible to establish that small doses of high-frequency ultrasound (0.2 ^ 1 W / cm2) cause a vasodilatory effect, large doses (3 W / cm2 and more) - a vasoconstrictor. Ultrasound has a noticeable effect on the tone of arteries of large and medium caliber. Changes in the activity of the gastrointestinal tract and other organs that develop under the action of high-frequency ultrasound are widely known. Researchers attribute the changes they observed to the effect of ultrasound on the hypothalamus, which regulates activity internal organs reflex and neurohumoral way.

Ultrasonic damaging changes in cochlear

apparatus and other tissues (bones) are interpreted as nonspecific, caused by vibration.

The mechanism of action of ultrasonic vibrations on the body is explained not only by the direct specific effect of ultrasound on nervous system, but also by reflex influence, carried out by the most complex cross reflexes.

The above information on the effect of high-frequency ultrasound on the body of animals and humans testifies to polymorphic and complex changes occurring in almost all tissues, organs and systems of the body, according to the degree of their resistance to ultrasound. Changes occur at the cellular, molecular and submicroscopic levels of tissues, resulting in a "restructuring" of physiological reactions, neurohumoral, metabolic processes, endocrine function and activity of various systems and organs, obeying a general pattern: low intensities stimulate, activate, medium and high inhibit, inhibit and can completely suppress functions.

Thus, this material, presented from the standpoint of the effect of ultrasound on biological systems, will help physicians navigate the choice of ultrasound parameters when using this therapeutic factor.

THE INFLUENCE OF ULTRASOUND ON THE ORGANISM

E.V. Shevchenko, N.A. Kchlopenko (Irkutsk State Medical University)

Its shown that main ultrasound charaecteristics (intensity, exposition duration, rate) establish the peculiarities of its spreading in medium and biotissues. A number of effects (mechanical, thermal and physical-chemical) occurs when the biotissues ifluenced by ultrasound. These effects result in some deviations from physical laws (principles) the nature of which is to be taken into the consideration when diagnostic and medical (theraupeutic) measures are performed.

LITERATURE

1. Mshsh / Yuv I.G. Ultrasound and its application. - L., 1968.

2. Ultrasound and thermodynamic properties. - Kursk,

3. Application of ultrasound to the study of matter. -

4. BogolYubov VA, Ponomarenko V.N. General physiotherapy. - M., 1998. - S. 239-259.

5. Bogolyubov V.A. Technique and methods of physiotherapy procedures. - M .: Medicine, "2002. - P.246-272.

6. Rudenko T.L. Physiotherapy. - Rostov-on-Don: Phoenix, 2000. - pp. 214-228.

7. MMlchanov G.I. Ultrasound in pharmacy. - M., 1980.-

8. Tsartsis P.G., Frenkel I.D. Biochemical basis of physical therapy or general physiotherapy. - M., 1987 .-- 453 p.

© BARDEDINOV H.K. - 2006

LECTURES ON FORMAL LOGIC: INTRODUCTION TO THE TEACHING ABOUT

CONCEPTS (Lecture 2)

H.K. Bardinov

(Irkutsk Institute for Advanced Training of Educators, Rector - Doctor of Historical Sciences, Prof. L.M.Dameshek, Department of Correctional and Developmental Education, Acting Head - Kh.K. Bardedinov)

Summary. It is known that in the process of training a specialist (doctor, lawyer, psychologist, teacher, journalist, etc.), not only the necessary knowledge is accumulated, but the so-called “professional” thinking is formed. This is a kind of mental activity of a specialist, suggesting special forms and relationships of analysis, synthesis, generalization, which are associated with the need to correlate the general (the general picture of the disease, the picture of behavior, crime, academic performance, etc.) with individual components (factors affecting behavior, academic performance, symptoms diseases, etc.). Professional thinking also involves making the only correct decision quickly and in a timely manner. A significant component in such thinking, in addition to intuitive and creative, is analytical (logical) thinking, which allows a specialist to create a picture of a situation in the form of clear thoughts - in the form of concepts, judgments, and conclusions. Key words. Thinking, logic, concept, content, specialist.

The logical theory is peculiar. She will tell you about ordinary human thinking that will seem to you at first glance unusual and unnecessarily

complicated. The main content of logic is often formulated in a special artificial language created specifically to formalize thought.

Ultrasound is called sound vibrations that exceed the upper limit of the range of sound frequencies perceived by a person. Such fluctuations can have a significant effect, which is currently widely used in different areas human activities - from building to scaring away rats. Like all other physical phenomena, ultrasound itself is neither harmful nor beneficial. Exposure to ultrasound is a powerful tool that, depending on the application, can be beneficial or harmful to health.

Ultrasound can be not only of different directivity, but also of different frequency and power. The frequency and power can be adjusted, due to which the effect of ultrasound can be used to cut granite, and can be used in the diagnosis of pregnant women. Surprisingly, in both cases, one physical phenomenon is used.

How does the impact of ultrasound on health? Also in different ways. If a person is in the affected area for a long time, then the health consequences can be sad. This is due to the fact that the human body is heterogeneous, and ultrasound, passing through various environments of the body, causes their various vibrations, which are disharmonious. If they occur for a long time, or even once, but have significant power, then they have a destructive effect on the cells of the body. Therefore, protective equipment has been developed for those people whose activities are associated with being in the zone of ultrasound exposure.

However, "tamed" ultrasound, adjusted so as not to cause disruptive changes, serves medical purposes. The effect of ultrasound is widely used in physiotherapy in order to enhance the regeneration of healing tissues, ultrasound helps to dissolve adhesions and scars, increases the permeability of the skin for medicinal substances (phonophoresis), is used for effective and safe exfoliation of dead skin cells of the epidermis - ultrasonic face peeling.

And of course, the well-known ultrasound diagnostics is a method that has become truly revolutionary in medicine, since it has a high information content and, at the same time, is quite cheap. And although rumors about the dangers of ultrasound periodically appear in the yellow press, they do not correspond to reality and come from people who are far from understanding the effects of ultrasound in therapeutic and diagnostic dosages. In many cases, ultrasound made it possible to abandon radiography, and if we compare the harmful effects of these two methods on the body, then undoubtedly the comparison will be in favor of ultrasound.

Ultrasonic waves are widely used in various fields of human activity.

Devices with ultrasonic generators are used for medical diagnostic procedures, for flaw detection, for performing ultrasonic welding, in various production processes, etc.

In addition to the above, ultrasound waves have found widespread use in everyday life and are used to scare off various pests: mice, rats, insects, etc.

For this, special devices have been created - ultrasonic scarers, which are installed both at industrial facilities and used at home. In this regard, the "amount of ultrasound" in human life has increased dramatically.

Naturally, the question arises as to whether the effect of ultrasound on the human body is dangerous at work and at home.

To give an affirmative answer to this difficult question, one should understand what ultrasonic waves are and how an ultrasound repeller, which a person uses in everyday life, functions.

What is ultrasound?

Ultrasound is a normal sound wave with a frequency higher than 20 kHz.

In other words, ultrasonic waves are elastic longitudinal vibrations that can propagate in any elastic medium in which they can create mechanical vibrations.

In air, ultrasonic waves propagate due to the vibrations of air molecules.

The frequency range, which is allocated for ultrasonic waves in the sound spectrum, is in the range of 20 ... 70 kHz.

It should also be noted that in addition to ultrasonic waves, there are also so-called infrasonic waves. They are also sound waves with a frequency of less than 16 Hz.

Many people believe that the impact of ultrasound and infrasound on the human body has negative consequences for it. Let's try to figure out whether this is really so.

How ultrasound affects the human body

The human hearing aid is designed in such a way that he can hear only those sounds that are in the frequency range from 10 Hz to 16 kHz, with the exception of some cases when a person, by his individuality, can hear sounds from a wider range.

Considering that ultrasonic frequencies are in the range from 20 kHz to 70 kHz, a person will not be able to hear them.

Therefore, there will be no discomfort and irritation from such waves for a person.

There is an opinion about the negative effects of ultrasound on the human brain and eardrums his hearing aid.

This is attributed to the fact that the ultrasound wave has strong pressure on human organs, which can lead to physical pain.

The fact is that ultrasonic, like any sound wave, is characterized by a certain sound pressure... Modern ultrasound devices form a wave, the pressure of which is in the range of 70 ... 100 dB.

As for a person, he can calmly endure the effects of waves, the sound pressure of which is 100 ... 120 dB. Therefore, it is not necessary to talk about the occurrence of painful sensations under the influence of an ultrasound wave with a maximum pressure of 100 dB.

Are ultrasonic scarers harmful?

The above is the effect of ultrasound on a person, consider whether these waves generated by ultrasonic repellers can harm a person.

Ultrasonic scarers spread ultrasonic waves, which have a frequency of about 20 kHz or more.

It changes periodically in automatic mode so that the pests do not get used to the operation of the device. As for the pressure of these waves, it is 70 ... 100 dB.

Rodents and other pests, which have a different structure of the hearing aid than humans, are able to perceive sounds characteristic of the ultrasonic range.

As a result, the propagation of waves from the ultrasound repeller will irritate and discomfort them.

In addition, given that the auditory system of rodents is very sensitive, waves with a sound pressure of more than 70 dB will cause them painful sensations, sometimes very strong.

Considering these two factors, which will continuously affect the rodents, the work of the repeller will lead to the fact that rats and mice will try to quickly leave the territories they occupy and never return there again.

As for humans, like most pets, the ultrasound emitted by scarers will not have a similar effect on them.

The only exceptions are those pets that are sensitive to ultrasound waves - these are guinea pigs, decorative mice, hamsters, hand rats, etc. Therefore, use of scarers based on ultrasound generators should be done with caution in those rooms where there may be such animals.

You should also take into account the fact that some devices, in addition to the ultrasound generator, can also have a conventional sound generator, which emits sound waves in the audibility spectrum of humans and pets.

Devices of this type should not be used at home; they can only be installed at production facilities in those rooms where people are absent.

Conclusion

If we study in detail the effect of ultrasound on the human body, then we can conclude that modern ultrasound scarers are harmless devices and can be used in places where a person is staying.

With the correct use of the repeller, it will only be beneficial - scaring away rats, mice and other pests, but not harm to humans.

Naturally, it is possible for someone, in view of the structural features of the body, ultrasound will have any effect, but this is an exception, not a pattern.

In order for the repeller to be truly safe for a person and ultrasound does not cause him discomfort, it is important to choose the right device for the appropriate conditions of use.

Today there are many different models that can be used in residential or industrial buildings. In order not to be mistaken with the choice, it is better to seek help from qualified specialists who will select a truly safe device.

And in conclusion, watch a video review of one of the scarers - the Torando 400 model

The human ear is capable of picking up sounds with a frequency ranging from 16 to 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, therefore, 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 effect of ultrasound, the 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 individual drugs, in physics and in everyday life.

What is ultrasound

Ultrasound is a high-frequency sound wave (its oscillation frequency exceeds tens and hundreds of thousands of hertz), capable of propagating in liquids, solid materials, and also in a gaseous medium, due to the action of elastic forces.

Ultrasound has both artificial and natural origins. So, in nature, bats, dolphins, whales, butterflies, grasshoppers, locusts, crickets, some species of birds and fish are endowed with the senses that allow reproducing and perceiving the vibrations created by the 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. They are also capable of detecting ultrasound from cats and dogs.

The propagation speed 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 rather quickly; conversely, in liquids and when passing through a solid, its strength decreases slowly. Unlike ordinary sounds propagating 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 the seas and oceans, to 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 harm the organisms that live in it. Under the influence of ultrasound, fish float up to the water surface with their belly upward, 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 the permissible limits, ultimately leads to extremely severe injuries, as well as the death of fish. In the same cases, when the effect of ultrasound is temporary, and its intensity is low, after its termination, the behavior and lifestyle of the fish becomes the same.

In a similar way, ultrasound affects a person. During the experiments, water was poured into the palm folded in the form of a bowl, and then the subject immersed the hand in an ultrasonic field. At the same time, he had unpleasant painful sensations. In general, we can say that the essence of the biological effects of ultrasound has not yet been fully understood. However, most likely, it is based on local pressures arising in tissues and on a local thermal effect directly related to the absorption of energy that occurs during damping of vibrations. Since liquids and gaseous media are capable of absorbing ultrasound well, and solids are capable of conducting it, the skeletal system of the human body is also a good conductor.

First of all, the effect of ultrasound provokes the appearance in a person of a thermal effect, which is a consequence of the transformation of the energy of an ultrasonic wave into heat.

In addition, it causes microscopic contractions and stretching of tissues (so-called micromassage) and stimulates blood circulation. As a result, the functions of various body tissues and blood flow are improved. Ultrasound is also able to have a stimulating effect on the course of metabolic processes and a neuro-reflex effect. Ultrasound causes changes not only in those organs that are affected by it, but also in other tissues and organs. At the same time, its 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 the tissues die off.

The ultrasonic wave is also capable of destroying many microorganisms, which makes it possible to inactivate viruses such as polio or encephalitis. The impact of ultrasound on a protein leads to disruption of the structure of its particles and their decay.

Under the influence of ultrasound, leukocytes and erythrocytes of blood are destroyed, and its viscosity and coagulability significantly increase, in addition, ROE is accelerated.

Ultrasound has a depressing effect on cell respiration, reduces the amount of oxygen consumed by it, and also contributes to the inactivation of certain enzymes and hormones.

Exposure to high-intensity ultrasound can lead to the following consequences for humans:

• Baldness;
• The onset of severe pain syndrome;
• Clouding of the cornea and lens of the eye;
• Hemolysis;
• Increased blood levels of cholesterol, uric and lactic acid;
• Minor hemorrhages in various tissues and organs of the body;
• Serious hearing impairment;
• Destruction of cells of Corti's organ;
• The destruction of nerve cells;
• Pathological development and destruction of bone tissue.

As a result of prolonged exposure to ultrasound, increased sleepiness, rapid fatigability, dizziness, manifestations of vegetative-vascular dystonia (memory impairment, sleep disorders, indecision, apathy, fearfulness, decreased appetite, tendency to depressive states, etc.).

Medical Exposure to Ultrasound

The healing properties of ultrasound are due to its ability to massage and warm tissues. However, the ultrasonic wave has a number of specific features of its effect on the body. You can deeply warm the tissue using different methods, but only the use of ultrasound allows to achieve good results in treatment.

In medicine, ultrasound is widely used not only to influence the focus of pain, but also for indirect influence. This achieves the following effects:

• Pain reliever;
• Antispasmodic;
• Anti-inflammatory;
• Bactericidal.

A combination of ultrasound exposure with other types of medical therapy is allowed. However, treatment must be carried out with great care. This is due to the high biological activity of the ultrasonic wave.