Vibration (Latin vibratio -. Kolebanie, jitter) - the mechanical vibrations. Vibration is also spoken in a more narrow sense, meaning the mechanical vibrations of an appreciable effect on the person.
A natural source of vibration are storms,earthquake. Artificially - different engines, vehicles, speakers, Percussive, etc. Passing through the valve, soil, floor, water, air vibrations can travel considerable distances and reach certain areas of the body or affect the whole person, causing local or general effects (local or general vibration).
Nothing goes unnoticed
The frequency spectrum of the vibration coversinfrasonic frequencies -. 16 Hz, audio - from 16 to 20,000 Hz and ultrasonic - more than 20000 Hz. The oscillation frequency capable of causing the most specific human vibratory sensation, is typically in the region up to 8000 Hz. Vibration is characterized as an irritant vibrational capacity and the duration of exposure.
The biological effect of vibration actiondetermined local intensity fluctuations of energy in the tissues causing variable voltage: compression and expansion, the shift from the natural resting axis torsion and bending tissues and fluids. Vibration facilitates the circulation of the fluid can cause decomposition of molecules in the cell cytoplasm (the internal fluid of the cell), intensifies enzymatic reactions, increases the permeability of cell membranes, can cause chromosomal rearrangements in the unit cell.
In addition, the vibration can cause a wholebody adjustment of many functions due to involvement in the reaction of the central nervous system and endocrine system. Moderate doses of non-intensive vibrations have a stimulating effect on the central nervous system, intensify the redox processes and activities of the pituitary, adrenal cortex, thyroid, etc., That is used for medicinal purposes. An increase in the dose of vibration leads to progressive functional and morphologic abnormalities in the body.
Ways to transfer vibration to the human body
As modes of transmission are distinguished:
overall vibration transmitted through the supporting surfaces on the body of a person sitting or standing;
local vibration transmitted through human hands or feet, and also through the arm in contact with vibrating surfaces.
Depending on the source of occurrence of the following types of vibration:
local vibration transmitted to humans from manual mechanized (with engines) instrument;
local vibration transmitted to humans from non-mechanized hand tools;
Vibration total of 1 category - transportation vibration effects on human workplaces vehicles moving on terrain, roads and so forth. " Example: tractors, trucks;
overall vibration 2 categories -transport and process the vibration effects on human workplaces cars moving on a specially prepared surfaces of production facilities, etc. Example: cranes, floor production trucks;..
Vibration total 3 categories - technologicalvibration effects on human workplaces stationary machines or pass on jobs that do not have sources of vibration. Example: machine tools, casting machine.
overall vibration in residential and public buildings from external sources. Example: vibration from passing trams.
overall vibration in residential and public buildings from internal sources. Example: elevators, refrigerators.
The occurrence of vibration
Vibration occurs in a variety oftechnical devices due to imperfection of their design, improper operation, external conditions (such as the relief of the roadway for vehicles), as well as a specially generated vibrations.
Effects on the body
Action vibrations per person is different. It depends on whether it involved the whole body or part of the frequency, intensity and duration, and so on. The impact of vibration can be limited to a feeling of tremors (pallesteziya) or lead to changes in the nervous, cardiovascular and musculoskeletal systems.
Due to the stress of vibrationviolations occur throughout the system interconnections neurohumoral regulation of functions and metabolism: affects the function of the cardiovascular, digestive, reproductive system, liver, kidneys, immune protection, etc. There may be internal injuries due to their displacement.
Thus, with prolonged exposurevibration a person develops vibration disease. Chronic exposure to vibration causes: swelling and bleeding in the brain and spinal cord, growth of connective tissue, edema, hemorrhage and degenerative changes in the organs, disorders of the blood. The arteries are changes similar to those of occlusive disease. Possible violations nourish the skin and its appendages (nails, hair, etc.), until the development of gangrene fingertips. The osteo-articular apparatus are developing osteoporosis, deforming arthrosis, osteochondropathy.