A human ear can pick up 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 special instruments are required to detect them.
It was a huge number of studies that analyzed the signs of a sound wave and the impact of ultrasound contributed to the emergence of prerequisites that allowed the use of ultrasound on a large scale in various industrial sectors, in the production of certain drugs, in medicine, physics, modern military equipment, biology, the national economy and everyday of life. Let us consider in more detail the effect of ultrasound on the human body.
What is ultrasound?
The effect of ultrasound and infrasound on the human body is unique. Ultrasound is a high frequency sound wave that can propagate in solid materials, in a liquid, and in a gaseous medium, due to the influence of elastic forces. The origin of ultrasound can be either natural or artificial. So, in nature, there are sensory organs that allow you to reproduce and receive vibrations generated by an ultrasonic wave, for example, in dolphins, bats, butterflies, whales, locusts, grasshoppers, crickets, certain species of fish and birds.
Thanks to this, they are able to perfectly navigate in space, including night time, as well as communicate with relatives. Dolphins and whales can send the necessary signals for tens of thousands of kilometers. In addition, dogs and cats can capture ultrasound. The intensity and speed of propagation of ultrasound are directly affected by the signs of the substance in which it is transmitted: if it moves away from a source in the air, then the sound weakens quite quickly. In liquids, as well as when passing through a solid, the strength of ultrasound decreases slowly. What is the effect of ultrasound on the human body?
Unlike ordinary sound
It differs from ordinary sound in that it spreads in all directions from the source. Ultrasound is essentially a narrow beam wave. Such features allow it to be used to study the seabed and ocean floor, to detect sunken ships and submarines, as well as various obstacles under water, and the exact distance.
But when propagated in water, ultrasonic waves can harm those organisms that live in it. Under the influence of ultrasound, the fish breaks the sense of equilibrium, they float up to the surface of the water upside down, and therefore can not assume their normal position. If the impact of ultrasound is intense and prolonged, exceeds the permissible limits, then in the end it will cause very serious damage and even death of the fish. If his influence is temporary, and the intensity is not too high, after the cessation of his lifestyle and behavior of fish return to their usual framework.
The effect on the human body of ultrasound
Ultrasound affects the human body in a similar way. During the experiment, water was poured into a palm-shaped palm, after which the subject immersed it in ultrasonic space. At the same time, he had painful discomfort. What effect of ultrasound on the human body, not everyone knows.
It is worth noting that the essence of the biological effect of ultrasound is still not fully understood. But with a higher probability, it is based on local pressures arising in the tissues, as well as the local thermal effect, which is directly related to the absorption of energy that occurs when vibration is suppressed. Since gaseous and liquid media are capable of perfectly absorbing ultrasound, while solids conduct it, the skeletal system of the human body is also a good conductor. Ultrasonic exposure in the human body primarily provokes the appearance of a thermal effect, which is a consequence of the energy transformation of an ultrasound wave into heat. What else do you need to know about ultrasound and its effect on the human body?
Stimulates blood circulation
In addition, it becomes the cause of microscopic stretching and contraction of the tissue (this is called micromassage), and also stimulates blood circulation. In this regard, there is an improvement in the functioning of various tissues of the human body and blood flow. In addition, ultrasound can have a stimulating effect on the course of metabolic processes and reflex-nerve action. It contributes to changes not only in the organs it affects, but also on other organs and tissues.
Harm of intense influence
At the same time, an intense and lasting effect destroys the cells and leads to their death. This is due to the fact that cavities form in body fluids under the influence of ultrasound (this phenomenon is called cavitation), due to which tissue dies. An ultrasound wave can also destroy many microorganisms, and this contributes to the inactivation of viruses such as encephalitis or poliomyelitis. The influence of ultrasound on the protein causes a violation of the structure of its constituent particles and their further decay. In addition, it destroys red blood cells and white blood cells in the blood, its coagulability and viscosity are significantly increased, and an acceleration of ROHE also occurs. An ultrasound wave inhibits cellular respiration, reduces the amount of oxygen consumed by it, and causes a number of hormones and enzymes to inactivate.
So the effect on the human body of ultrasound is still not very good.
Consequences for the human body
High-intensity ultrasound can cause the following effects in humans:
- the appearance of increased pain;
- baldness;
- hemolysis;
- clouding of the lens and cornea of the eye;
- increase in the content of lactic and uric acid, cholesterol in the blood;
- small hemorrhages in a number of organs and tissues of the body;
- significant hearing impairment;
- pathological formation and destruction of bone tissue;
- destruction of nerve cells and cells of the organ of Corti. These are the main diseases caused by exposure to ultrasound.
As a result of the prolonged influence of ultrasound, excessive drowsiness, dizziness, high fatigue, and symptoms of vegetative-vascular dystonia (sleep disorders, memory defects, apathy, indecision, decreased appetite, timidity, tendency to depression, etc.) appear.
Where is the most common effect of ultrasound on the body?
The use of ultrasound in the field of medicine
The therapeutic effect of ultrasound is due to its ability to penetrate into tissues, their heating and 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 in some cases a positive effect occurs only after using ultrasound.
Given the reflex mechanism, ultrasound can be used not only to directly affect the epicenter of pain, but also to influence indirectly.
Due to the properties indicated above, under a number of conditions, ultrasound 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 in its therapeutic use have been obtained in a number of diseases. It is very effective in the treatment of neuralgia, myalgia, amputated limb neuritis, periarthritis, arthritis and arthrosis. Whether ultrasound is harmful to humans is interesting to many.
Total impact
The general effect of ultrasound on the human body is confirmed, in particular, by the fact that in case of damage to a number of joints, it is often enough to confine oneself to the therapy of any of them, since a parallel improvement of the remaining joints is noted. Positive results were obtained with ultrasound treatment of spondylitis, ankylosing spondylitis, varicose, sluggishly granulating and trophic ulcers, obliterating endarteritis.
There are separate indications of the positive use of ultrasound for bronchial asthma, duodenal ulcer and stomach ulcer, bronchiectasis, pulmonary emphysema, Meniere's disease and otosclerosis. There are also observations that indicate that preliminary skin sonication enhances the effectiveness of x-ray irradiation.
Contraindications to the use of ultrasound
It is forbidden to voice the genitals, growing bones, tumors, heart areas (this can cause angina pectoris). With hypertension, pulmonary tuberculosis, pregnancy, hyperthyroidism, changes in parenchymal organs, the use of ultrasound is also contraindicated. If it is used on an ever larger scale, it is necessary to organize careful monitoring of patients who come in contact with ultrasound in order to identify early symptoms of the disease and in time to carry out the required preventive and therapeutic measures. There is also evidence of a positive effect of ultrasound on some forms of neuritis and cancer. But the width of the safe area between the positive and the damaging effect has not yet been determined with accuracy.
We examined the effect of ultrasound on the human body.