What is the nature of infrared ray?
What are its basic characteristics? To understand these problems, we must first understand what electromagnetic waves are. Common sense of physics tells us that there is an electric field around any charged object, which exerts a force on other charged objects. Similarly, a magnetic field around a magnet or other magnets exerts a force on other ferromagnetic substances. Although these two fields are invisible and intangible, they do exist objectively, and their existence can be confirmed by testing instruments. Physicists have found that at any point in space, when the electric field intensity changes, a magnetic field or magnetic field intensity around that point changes; On the contrary, when the intensity of a magnetic field changes, it will definitely cause a new electric field or a change in the intensity of the electric field around the point. In other words, the changing electric field and the changing magnetic field do not exist in isolation, they are interrelated and mutually excited to form a unified electromagnetic field. The so-called electromagnetic wave is caused by the vibration of the electromagnetic field. Like the vibration of water molecules, it propagates from near to far into space. Since it is a wave, there must be a theory of wavelength and frequency. The former refers to the length of electromagnetic waves, often in microns, millimeters, centimeters and meters. The latter refers to the speed of electromagnetic field vibration, that is, the number of vibrations per second, often in hertz (1 Hz = 1 times per second), kilohertz and megahertz.
Scientists have confirmed that electromagnetic waves travel at the same speed as light, that is, 300,000 kilometers per second. Therefore, the relationship between wavelength and frequency can be calculated according to the following formula:
Wavelength = speed/frequency
In general science books or electronic instrument manuals, as long as the wavelength is mentioned, you will always be told how many frequencies. And it can be seen from this formula that the shorter the wavelength, the higher the frequency, because the speed is constant.
At this point, the concept of electromagnetic wave has been basically clear, and its essence is produced by the motion of charged particles of atoms and molecules that make up an object. It is an objective substance and does not need to be spread through the media.
Understand the basic concept of electromagnetic wave, and the problem of thermal radiation will be solved. For an object with a certain temperature, the electromagnetic spectrum it emits is certain, and the electromagnetic radiation with this characteristic is called thermal radiation. Infrared ray means that when an object is in a temperature range of one to one, it will emit electromagnetic waves with longer wavelength. Therefore, if electromagnetic wave is compared to a big family, thermal radiation is a small family in this big family, and infrared ray is a member of this small family.
Infrared has a wide wavelength range, so it is often divided into three regions: near infrared, middle infrared and far infrared. According to the different requirements of users, the division scope is also very different. For example, someone divides the three bands that can pass through the atmosphere into:
Near infrared band 1 ~ 3 microns
Mid-infrared band 3 ~ 5 microns
Far infrared band 8 ~ 14 micron
Someone according to the infrared spectrum is divided into:
Near infrared band 1 ~ 3 microns
Mid-infrared band 3 ~ 40 microns
Far infrared band 40 ~ 1000 micron
The medical field is usually divided like this:
Near infrared region 0.76 ~ 3 microns
The mid-infrared region is 3 ~ 30 microns.
Far infrared region 30 ~ 1000 micron
However, in practical applications, infrared rays above 2.5 microwaves are generally called far infrared rays.
Infrared ray:
Infrared ray is one of the many invisible rays of the sun, which was discovered by the German scientist Huxley in 1800. It is also called infrared radiation.
In recent years, due to the improvement of test equipment and in-depth research, people have a more comprehensive understanding of the physical properties and biological effects of infrared rays, and have made a lot of progress. Infrared rays, especially far infrared rays, have been widely used in health care industry, and various infrared products related to daily life have also appeared in large numbers.
First, the mechanism of infrared biological effect
Infrared rays have strong penetrating power to human skin and subcutaneous tissue. The primary effect of external infrared radiation on human body is to raise the temperature of skin and subcutaneous tissue, promote blood circulation and metabolism, and promote human health.
The thermal effect, anti-inflammatory effect and promoting regeneration of infrared physiotherapy on tissues have been clinically confirmed. Usually, direct irradiation is used to treat diseased parts.
Near-infrared micro-irradiation therapy has a significant effect on improving microcirculation, especially micro-blood flow. After irradiation, the blood flow velocity of capillaries is accelerated, the phenomenon of red blood cell aggregation is reduced, and the phenomenon of blood stasis in inferior papillary venous plexus is alleviated or disappeared, which has a positive effect on improving the nutrition, metabolism, repair and function of body tissues and important organs. At present, the mechanism of the secondary effect of infrared rays on human body is not completely clear.
Some scholars believe that far infrared rays can vibrate cells, mainly causing the vibration of water molecules inside and outside cells, activating cells and causing a series of healthy biochemical and histochemical changes of cells.
Some people think that far infrared rays can be called "life rays" and can significantly improve human microcirculation. When it acts on water molecules in human body, it can vibrate the aging macromolecules in human body, and make them crack and recombine into smaller water masses, thus enhancing the activity and surface tension of cells. Due to the increase of water molecules penetrating the cell membrane, the activity of intracellular calcium ions is enhanced, thus enhancing the normal function of human cells and improving their bactericidal ability and immune ability.
In addition, the light of life can also cut off the double or triple bonds of unsaturated fatty acids in blood, and saturated fatty acids are not easy to be oxidized into blood lipids [lipid peroxides], thus reducing the deposition of lipids in blood vessels and smoothing the blood vessel wall, thus reducing the occurrence of cardiovascular diseases or ophthalmic diseases such as arteriosclerosis and cataracts, and playing a good role in promoting human health.
Pang Xiaofeng's research on the biological effects and medical effects of infrared rays on organisms (including people) mainly comes from the non-thermal biological effects of infrared rays. The absorption of infrared rays can lead to the quantum vibration of amide bonds in protein molecules, so that biological energy can be smoothly transferred from one place to another, and the living body can be in a normal state, maintaining growth, development and health.
The research on the effect of infrared ray on immune function is still in its infancy. Among all infrared rays, medium-wave infrared rays are more likely to act on immune cells and promote their biological functions. The function of infrared ray is not only related to its wavelength, but also related to the number of photons it emits, that is, to the radiation intensity and radiation time. Excessive infrared radiation may also have adverse effects on the body, and its detailed mechanism needs to be further clarified.
Cao Zhiran and others believe that infrared radiation has indirect and direct effects on human immune system. Indirect effect means that infrared radiation can regulate the state of other systems of the body, such as nervous system and endocrine system, so as to achieve the purpose of regulating the immune system. Direct action means that infrared rays can enhance the biological field around immune cells and immune organs after being absorbed by human body, thus enhancing their activity and mutual regulation. Infrared photons can directly act on the exciting points of immune cells.
Mao Wen and others speculate that the mechanism of action is that infrared rays may activate deep tissue receptors, and its physiological and biochemical effects, on the one hand, have a positive impact on the activities of biological macromolecules, cells and organs through neurohumoral reflex pathways and meridian conduction pathways that have not been fully understood at present, thus producing overall benign effects [2].
Second, the possible adverse effects of infrared rays on the human body
Thermal radiation, also known as infrared radiation, is the main feature of high temperature working environment in iron and steel metallurgical enterprises. Especially in the hot rolling and medium sintering machines of iron and steel smelting and Honggang, it is a typical infrared thermal radiation contact operation. Short-wave infrared rays can penetrate the cornea and enter the eyeball, aqueous humor, iris, lens and vitreous humor to absorb some infrared rays and cause cataracts, which are called "infrared cataracts".
It has also been pointed out that the harm of ultraviolet rays (UVR) and infrared rays (IFR) to eyes and skin is an important aspect of occupational injury in electric welding, and ultraviolet rays and infrared rays in the process of electric welding can cause damage to cornea and lens [7].
Infrared rays in sunlight do different harm to the skin than ultraviolet rays. Ultraviolet light mainly causes photochemical reaction and photo-immune reaction, while infrared radiation causes reactions caused by molecular vibration and temperature rise.
The thermal radiation caused by infrared rays can penetrate the skin more than ultraviolet rays. Infrared rays have direct adverse effects on the skin through its thermal radiation effect, such as skin temperature rise, capillary dilation, congestion, and increased evaporation of epidermal water. Its main manifestations are red papules, premature aging of skin and pigment disorder. The increase of skin temperature, telangiectasia and congestion, and the increase of epidermal water evaporation have direct adverse effects on the skin.
Infrared rays can also enhance the damage of ultraviolet rays to the skin and accelerate the process of skin aging. This is caused by the dual effects of ultraviolet and infrared rays on the skin under natural sunlight. Infrared rays and ultraviolet rays have the same effect in accelerating tissue degradation. Infrared rays can also promote the development of skin cancer caused by ultraviolet rays.
Third, the clinical application of infrared biological effects.
Infrared rays can be absorbed by superficial tissues on the body surface, which has obvious drying and dehydration effects, accelerates the blood circulation of local tissues, and plays an anti-inflammatory and analgesic role. Clinical application of safflower oil and far-infrared radiation to treat bedsore has found good effect and quick effect.
The far infrared ray was used to treat herpes zoster. The results showed that the pain relief time, blister stop time and dementia time were shorter than those of the control group. Experiments show that bioceramic far infrared rays have a significant effect on burn treatment. Chronic soft tissue injury is the best way to treat traumatic pain. Clinical nursing observation shows that far-infrared protective devices made of ultrafine ceramic particles, such as waist protection, knee protection, elbow protection, wrist protection, collar and so on. It has obvious functions of diminishing inflammation, reducing swelling, promoting blood circulation, relieving pain, dredging meridians and improving microcirculation. At the same time, it can avoid the pain caused by closing. Far infrared radiation and hotbed were used to treat children's red buttock and buttock ulcer. Compared with the control group, the average cure time of the treatment group is shorter and the effective rate is higher.
The problem of rewarming in the treatment of neonatal scleredema is an important link in the success of treatment. In the past, the effect of gradual rewarming with ordinary warm box was poor. Now, after rapid rewarming with far infrared rays, the mortality rate of children is obviously reduced and the success rate of rescue is obviously improved. Skin flap necrosis is a common postoperative complication in plastic surgery, mainly caused by microcirculation disturbance, and there is no ideal prevention and treatment method at present. In vivo, ginger directly observed the microcirculation changes of any skin flap on the back of rats. It is found that far infrared local radiation has biological effects similar to vasodilators, which can improve microcirculation and improve the survival rate of skin flap, and has no obvious side effects within the therapeutic dose range. Some scholars in Japan reported that the linear polarized infrared ray was effective in treating various types of alopecia areata.
Linear polarized near infrared ray is effective in treating temporomandibular joint pain caused by rheumatoid arthritis. The mechanism may be that light can stimulate photoelectric energy, electromagnetic waves and photochemical action, so it can inhibit nerve excitement, relax muscles, relax blood vessels, increase blood flow, promote lymphatic circulation and promote the production of active factors, thus playing a therapeutic role. By observing the blood viscosity before and after the treatment of far infrared rays, it is found that low-temperature excitation of far infrared rays has a wide range of biological effects, mainly the low-temperature thermodynamic effect, which can reduce the blood viscosity of patients with cardiovascular and cerebrovascular diseases, prevent thrombosis, improve microcirculation, and relieve chest tightness, palpitation, dizziness, numbness and other symptoms. Compared with other drug therapies, infrared irradiation of bladder area is painless, does not increase postpartum hemorrhage, and is easy to be accepted by parturient. Some people use far-infrared radiation to treat children's enterospasm 2, and find that its curative effect is obviously better than that of drug treatment, and it is simple and easy, without side effects, and children are willing to accept it. Infrared radiation can obviously alleviate the hyperglycemia of diabetic rabbits, and the blood sugar will also decrease accordingly. Mid-far infrared therapy can enhance the ability of tumor host to scavenge free radicals and inhibit the growth and proliferation of tumor cells.