Infrared ray is one of the many invisible rays in the sun. It was discovered by the German scientist Horschel in 1800. It is also called infrared thermal radiation. He decomposed the sunlight with a prism. Thermometers were placed in place of various colored ribbons in an attempt to measure the heating effect of various colors of light. It was found that the thermometer outside the red light heated up the fastest. Therefore, it is concluded that in the solar spectrum, there must be invisible light outside the red light, which is infrared. It can also be used as a medium for transmission. The wavelength of infrared rays in the solar spectrum is larger than visible light, with a wavelength of 0.75 to 1000 μm. Infrared rays can be divided into three parts, namely near infrared rays, with wavelengths between 0.75 and 1.50 μm; mid-infrared rays, with wavelengths between 1.50 and 6.0 μm; and far infrared rays, with wavelengths between 6.0 and 1000 μm.
The real infrared night vision device uses photomultiplier tube imaging, which is completely different from the principle of a telescope. It cannot be used during the day, is expensive, and requires a power supply to work.
Physical properties of infrared rays
In the spectrum, the wavelength range from 0.76 to 400 microns is called infrared rays. Infrared rays are invisible light. All substances above absolute zero (-273°C) can produce infrared rays. Modern physics calls them heat rays. Medical infrared rays can be divided into two categories: near infrared rays and far infrared rays.
Near-infrared rays, or short-wave infrared rays, have a wavelength of 0.76 to 1.5 microns, and penetrate deep into human tissue, about 5 to 10 millimeters; far infrared rays, or long-wave infrared rays, have a wavelength of 1.5 to 400 microns, and are mostly penetrated by the surface layer of skin. Absorbed and penetrates tissue to a depth of less than 2 mm.
Physiological and therapeutic effects of infrared rays
Reflection and absorption of infrared rays by the human body
After infrared rays irradiate the body surface, part of it is reflected and the other part is absorbed by the skin . The degree of skin reflection of infrared rays is related to the condition of pigmentation. When irradiated with infrared rays with a wavelength of 0.9 microns, skin without pigmentation reflects about 60% of its energy; while skin with pigmentation reflects about 40% of its energy. When long-wave infrared rays (wavelengths above 1.5 microns) are irradiated, most of them are reflected and absorbed by superficial skin tissues, and the depth of penetrating the skin is only 0.05 to 2 mm, so they can only affect the surface tissue of the skin; short-wave infrared rays (wavelengths above) are Within 1.5 microns) and the near-infrared part of red light penetrates the deepest into tissues, with a penetration depth of up to 10 mm, and can directly affect blood vessels, lymphatic vessels, nerve endings and other subcutaneous tissues of the skin.
Infrared erythema
When infrared rays of sufficient intensity irradiate the skin, infrared erythema may appear. The erythema will disappear soon after the irradiation is stopped. When large doses of infrared rays are irradiated to the skin multiple times, brown marble-like pigmentation can occur. This is related to the fact that the heat effect strengthens the pigment formation of melanocytes in the basal cell layer of the blood vessel wall.
The therapeutic effect of infrared rays
The basis of the therapeutic effect of infrared rays is the warming effect. Under infrared irradiation, tissue temperature increases, capillaries dilate, blood flow accelerates, material metabolism increases, and tissue cell vitality and regeneration capacity increase. When infrared treats chronic inflammation, it improves blood circulation, increases the phagocytosis function of cells, eliminates swelling, and promotes the dissipation of inflammation. Infrared rays can reduce the excitability of the nervous system, have analgesic effects, relieve spasms of striated and smooth muscles, and promote the recovery of neurological functions. When treating chronic infectious wounds and chronic ulcers, it improves tissue nutrition, eliminates granuledema, promotes granulation growth, and accelerates wound healing. Infrared irradiation can reduce exudation from burn wounds. Infrared rays are also often used to treat sprains and contusions, promote the dissipation of tissue swelling and hematoma, reduce postoperative adhesions, promote scar softening, and reduce scar contracture.
The effect of infrared rays on the eyes
Since the eyeball contains a lot of fluid and has strong absorption of infrared rays, cataracts can be caused when infrared rays of a certain intensity are directly irradiated into the eyes. The occurrence of cataracts is related to the effect of short-wave infrared rays; infrared rays with wavelengths greater than 1.5 microns do not cause cataracts.
The effect of light bath on the body
The factors that work in light bath are infrared rays, visible light and hot air. Light bathing can make a larger area or even the whole body sweat, thereby reducing the burden on the kidneys, improving blood circulation in the kidneys, and conducive to the recovery of kidney function. The effect of light bath can increase hemoglobin, red blood cells, neutrophils, lymphocytes, and eosinophils, and slightly shift the nucleus to the left; strengthening immunity. Local baths improve blood supply and nutrition to the nerves and muscles, thereby promoting their normal function. Whole-body light bathing can significantly affect the metabolic process in the body and increase the burden of whole-body heat regulation; it also has a certain impact on the autonomic nervous system and cardiovascular system.
Equipment and treatment methods
Infrared light source
1. Infrared radiator
Wrap the resistance wire around the porcelain rod and energize it The resistance wire generates heat, which causes the temperature of the carbon rod covering the resistance wire to rise (generally not exceeding 500°C), and emits mainly long-wave infrared rays.
There are two types of infrared radiators: standing type and portable type. The power of standing infrared radiators can reach 600 to 1000 watts or more.
In recent years, far-infrared radiators have been manufactured in some areas of our country for medical use. For example, far-infrared radiators can be made using high-silica components.
2. Incandescent lamp
Incandescent bulbs of various powers are widely used as infrared light sources in medical treatment. The temperature of the tungsten filament in the light bulb can reach 2000~2500℃ after being energized.
Incandescent lamps are used in phototherapy in the following forms:
Standing incandescent lamps: Use incandescent bulbs with a power of 250 to 1000W, and install a metal mesh between the reflectors. Think of protection. Standing incandescent lamps, often called sun lamps.
Portable incandescent lamp: an incandescent bulb with a smaller power (mostly below 200W) is installed in a small reflector, and the reflector is fixed on a small bracket.
3. Light bath device
It can be divided into two types: partial or whole body irradiation. Depending on the size of the light bath box, 6 to 30 40-60W light bulbs can be installed in the box. The light bath box is semicircular, and a small metal reflector can be added to the part where the light bulb is fixed in the box. The whole body sunbath box should be equipped with a thermometer so that the temperature inside the box can be observed and adjusted at any time.
How to operate infrared therapy
1. The patient takes an appropriate position and exposes the irradiated area.
2. Check whether the warmth sensation in the irradiated area is normal.
3. Move the lamp above or to the side of the irradiated part. The distance is generally as follows:
For power above 500W, the lamp distance should be above 50~60cm; for power 250~300W, The lamp distance is 30~40cm; the power is below 200W, and the lamp distance is about 20cm.
4. When applying partial or whole-body light bathing, both ends of the light bathing box need to be covered with sheets. 3 to 5 minutes after powering on, the patient should be asked whether the warmth sensation is appropriate; the temperature in the light bath box should be maintained at 40 to 50°C.
5. Each irradiation lasts for 15 to 30 minutes, 1 to 2 times a day, and 15 to 20 times is a course of treatment.
6. At the end of the treatment, dry the sweat from the irradiated area, and the patient should rest indoors for 10 to 15 minutes before going out.
[Attached] Precautions
(1) The patient must not move during treatment to prevent burns.
(2) If you feel overheated, palpitation, dizziness or other reactions during the exposure, please inform the staff immediately.
(3) When the irradiated part is close to the eyes or the light can reach the eyes, the eyes should be covered with gauze.
(4) When the affected area has thermal sensory impairment or when irradiating fresh scars or skin grafting areas, apply a small dose and closely observe local reactions to avoid burns.
(5) Infrared irradiation is generally not used in areas with blood circulation disorders, obvious capillaries or dilated blood vessels.
Selection of irradiation methods and irradiation dose
1. Selection of different irradiation methods
Infrared irradiation is mainly used for local treatment. In individual cases, such as children Infrared rays can also be used in conjunction with whole-body ultraviolet irradiation for full-body irradiation. If local irradiation requires a deeper thermal effect, incandescent lamps (i.e. solar lamps) are preferred. Local light bath can be used to treat chronic rheumatoid arthritis; whole-body light bath can be used to treat multiple peripheral neuritis.
2. Irradiation dose The dose of infrared treatment is determined mainly based on the characteristics and location of the lesion, the age of the patient and the functional status of the body. When exposed to infrared rays, the patient will feel a comfortable feeling of warmth, and light red and uniform erythema may appear on the skin. Marble-like erythema may indicate overheating. The skin temperature should not exceed 45℃, otherwise it may cause burns.
Main indications and contraindications
(1) Indications
Rheumatoid arthritis, chronic bronchitis, pleurisy, chronic gastritis, chronic enteritis, neurological disease Radiculitis, neuritis, multiple peripheral neuritis, spastic paralysis, flaccid paralysis, peripheral nerve trauma, soft tissue trauma, chronic wounds, frostbite, burn wounds, bedsores, chronic lymphadenitis, chronic phlebitis, post-injection induration, postoperative Adhesions, scar contracture, postpartum agalactia, cracked nipples, vulvitis, chronic pelvic inflammatory disease, eczema, neurodermatitis, skin ulcers, etc.
(2) Contraindications
Bleeding tendency, high fever, active pulmonary tuberculosis, severe arteriosclerosis, obliterans vasculitis, etc.
[Attached] Examples of prescriptions
(1) Infrared irradiation of both knee joints
The lamp distance is 40cm, 30 minutes, once a day, 7 times.
Indications: Chronic rheumatoid arthritis
(2) Infrared irradiation of the right thorax (lower part)
The lamp distance is 50cm, 20 minutes, every Once a day, 8 times.
Indications: Right dry pleurisy
(3) Sun lamp irradiation of lumbosacral region
Lamp distance 40cm, 20-30 minutes, once a day , 6 times.
Indications: lumbosacral radiculitis
(4) Full body light bath
The temperature in the box is 40~45℃, 20~30 minutes, daily Once, 8 times.
Indications: Multiple peripheral neuritis
(5) Local light bath on the left calf
20 to 30 minutes, once a day, 8 times.
Indications: left common peroneal nerve trauma
Infrared pollution
In recent years, infrared rays have been used in military, artificial satellites, industry, health, scientific research, etc. As it becomes increasingly widespread, the problem of infrared pollution also arises. Infrared ray is a kind of thermal radiation that can cause high temperature damage to the human body. Strong infrared rays can cause skin damage similar to scalding, with burning pain at first and then burns. Infrared rays can cause damage to the eyes in several different ways. Infrared rays with a wavelength of 7,500 to 13,000 angstroms have a high transmittance to the cornea and can cause damage to the retina of the fundus. In particular, infrared rays near 11,000 angstroms can protect the front media of the eye (corneal lens, etc.) from damage and directly cause retinal burns in the fundus of the eye. Infrared rays with wavelengths above 19,000 angstroms are almost entirely absorbed by the cornea and can cause corneal burns (turbidity, white spots). Most of the energy of infrared rays with wavelengths greater than 14,000 Angstroms is absorbed by the cornea and intraocular fluid and cannot penetrate the iris. Only infrared rays below 13,000 Angstroms can penetrate the iris and cause iris damage. Cataracts may occur if the human eye is exposed to infrared rays for a long time.
Infrared rays can be produced artificially and are widely found in nature. Generally, living things will radiate infrared rays, and the macroscopic effect is heat.
We know that the cause of heat generation is The particles that make up matter move irregularly. This movement also radiates electromagnetic waves, most of which are infrared.
1. The sunlight is indeed almost gone at night, but the materials on the earth will Radiation infrared rays, some are strong and some are calm. Infrared photography is to receive infrared rays emitted by various substances and then display them, but it does not take pictures by emitting infrared rays.
2. Infrared perspective and night vision respectively make use of the different properties of infrared rays. The former night vision is because the human eye cannot see infrared rays, but specially designed cameras and night vision devices specifically accept infrared rays. Therefore, we feel that it is pitch black, but the camera can Capture something. Because infrared rays are actually everywhere, it is bright for infrared cameras and night vision devices.
Perspective is the use of infrared rays whose wavelength is longer than visible light, and can pass through some visible light that cannot. passing fabrics (such as mixed cotton and nylon), so through certain selection filters, the images behind these fabrics can be obtained.