Infrared Radiation (IRR) PDF

Infrared Radiation (IRR) Dr. Mohamed Yahia Lecturer of Basic science  Infrared Radiation (IRR) Definition: Infrared radiations are electromagnetic waves with wavelengths of 750 to 400.000 nm and frequency 4 × 1014 Hz and 7.5 × 1011 Hz which longer than those of visible light It...

Infrared Radiation (IRR) Dr. Mohamed Yahia Lecturer of Basic science  Infrared Radiation (IRR) Definition: Infrared radiations are electromagnetic waves with wavelengths of 750 to 400.000 nm and frequency 4 × 1014 Hz and 7.5 × 1011 Hz which longer than those of visible light It is therefore generally invisible to the human eye. Any hot body can produce infrared rays like the sun, electric bulb, coal fire, gas fire, etc. Sun is the natural source of infrared radiations. Infrared radiations can be produced by artificial generators. In the Physiotherapy departments infrared rays are produced by two types of generators: 1. Non-luminous generators.(IRR) ONLY 2. Luminous generators. (IRR), (UV)and visible light And another classification due to wavelength are: A. Near (short) infrared. B. Far (long) infrared. 1. Non-luminous generators: consists of a simple type of element or coil wound on a cylinder of some insulating material such as porcelain. An electric current is passed through the wire which results in the production of heat. This heat produces infrared rays In another type of non-luminous generator, a steel tube within which an electric coil is embedded on some material which is electric insulator but good conductor of heat is used.  Electric current is passed through the central coil and thus heat is produced. All of these non-luminous generators take some time to get heated up for the production of infrared radiations, so they should be switched on before 5–7 minutes of the treatment. non-luminous generators 2. Luminous Generators: These generators are in the form of incandescent lamps or bulbs. An incandescent lamp consists of a wire filament enclosed in a glass bulb, which may contain an inert gas at low pressure. the maximum proportion of the rays having wavelength in the region of 1000 nm. The front of the bulb is usually red so as to filter out the shorter visible and the ultraviolet rays.  Depth of Penetration of Rays Luminous generator produces infrared rays having wavelength between 350 and 4000 nm. It can penetrate into dermis and epidermis of the subcutaneous tissue. Non-luminous generator produces infrared rays of wavelength 750 to 15000 nm which can penetrate the superficial dermis only. Thus, infrared rays produced from a luminous generator have more penetration power than that produced from non-luminous generator. When there is acute inflammation or recent injury, the sedative effect of rays obtained from non-luminous generator may prove more effective for relieving pain than the counter-irritant effect of those from the luminous source. For lesions of a more chronic type, the counter-irritant effect of the shorter rays may prove to be of value, and under these circumstances a luminous generator is chosen. Selection of the generator according to the area to be treated is done. If only one surface is to be treated, a lamp of a single element mounted on a reflector is used. If several aspects are required to be irradiated, a tunnel bath is more effective.  The temperature reached in a tunnel bath is higher than produced by other lamps and this may be advantage if chronic lesions are to be treated 1. Near (short) infrared. It's the type of infrared light nearest to the visible light spectrum what's most of the sun’s infrared spectrum is composed of. 2. Far (long) infrared. Far infrared is mainly absorbed by the water within our bodies and for that reason penetrates only < 5mm beneath the skin.  Physiological effects Infrared treatment produces heating effect in the superficial epidermis and dermis, thus resulting in vasodilatation which increases blood circulation in that area. This will lead to more oxygen supply and nutrient supply in that area leading to draining of waste products resulting in the relief of pain.  Indications and Therapeutic Effects (A)Relieving pain: Infrared radiations are effective in relieving pain.  Mild heating on the superficial tissues by infrared radiations causes sedative effects on the superficial sensory nerve endings.  Pain may be due to accumulation of waste products of metabolism; an increased flow of blood through the part removes these substances and thus relieves the pain.  The pain due to acute inflammation or recent injury is relieved most effectively by mild heating.  When pain is due to chronic injury or inflammation, stronger heating is required.  The treatment may last up to 30 minutes. (B) Muscle relaxation: Relaxation of muscles is achieved by heating the tissues. Mild heating by infrared causes relaxation of muscles and thus relieves spasm. Relief of pain also induces relaxation in muscles and helps relieving muscle spasm associated with injury or inflammation.  Relaxation of muscles provides greater range of motion to the exercising part as it relieves muscular spasm. (C)Increasing blood supply: Infrared radiations increase the temperature in the superficial tissues, causing vasodilatation in the superficial tissues. It provides more white blood cells and fresh nutrients to the area being treated. It also accelerates It is most beneficial in the treatment of various arthritic conditions of joints which leads to inflammation and stiffness. Cases of post-immobilization stiffness. Fresh supply of blood rejuvenates the tissues, removes waste products of metabolism and also relieves muscular spasm. (D)Prior to other Treatments: (e.g. stretching, mobilization, traction, massage, exercise therapy, electrical stimulation, and biofeedback).  Dangers of Infrared Radiations 1. Burn: Excessive heating of superficial tissues causes burn. Sensation must be checked before starting the treatment. The burn may be caused due to the following reasons: 1. If intensity of radiation is too high 2. If sensation is not proper 3. Patient fails to report over heating 4. Unconscious patient 5. Patient moves closer to the lamp 6. Falls asleep during the treatment. The patient must be warned to inform undue heating immediately. The spacing must be reduced gradually in order to increase the heating. Impaired blood flow through the part, which may be due to some circulatory defect or due tight garments reduces circulation and thus causes burn. 2.Electric shock: Electric shock can occur if some exposed part of the circuit is touched by the patient. Due to heating of the wires in the circuit, insulation of wires may go off and thus regular checking of wires is necessary to avoid electric shock. 3.Faintness or giddiness: Extensive irradiation may cause fall in blood pressure which may result in faintness or giddiness due to hypoxia of the brain. This is particularly common when the patient rises up suddenly from the recumbent position after extensive treatment. 4. Headache: Irradiation of the back of the head may cause headache. Headache may also occur when treatment is given during hot weather. Lots of fluid goes off the body in the form of sweating during treatment. Plenty of water needs to be replenished during or after the treatment especially in hot weather. 5. Gangrene: Gangrene may be caused in the areas of defective arterial blood supply following prolonged irradiation by infrared radiation. Arterial supply to the area being treated needs to be proper to avoid gangrene. 6. Injury to the eyes: Direct heating over the eyes causes drying up and thus leads to corneal or retinal burns. Eyes need to be protected following treatment to avoid injury.  CONTRAINDICATIONS 1. Defective arterial blood supply 2. Areas where there is danger of hemorrhage 3. Defective skin sensation 4. Directly over the eyes  5. after deep X-ray or cobalt therapy 6. Known cases of tumors. 7. Acute inflammatory conditions. 8. Acute skin diseases e.g., dermatitis or eczema.