Ultraviolet radiation

Ultraviolet radiation for physiotherapy

1. Ultraviolet radiations By : ANNIE BLESSIE

2. Contents D efinition Types of UVR Production of UVR Physiological effects Indications Contraindications Dangers 07-06-2020 [email protected] 2

3. Definition Ultraviolet radiations are the electromagnetic energy which falls between visible rays and X-rays and have wavelength between 10 nm and 400 nm. Ultraviolet radiations are invisible to the human eye Ultraviolet radiations transmit much more energy than the visible radiations . The therapeutic part of the ultraviolet spectrum may be divided into: UVA : Wavelength 315–400 nm UVB : Wavelength 280–315 nm UVC : Wavelength below 280 nm 07-06-2020 [email protected] 3

4. Production of UVR Ultraviolet rays are emitted by the sun but for therapeutic purposes, some form of generator is used. Generators produce ultraviolet rays from mercury. Various types of generators are used such as : High pressure mercury vapour lamp Kromayer’s lamp Fluorescent tubes T heraktin tunnel PUVA apparatus 07-06-2020 [email protected] 4

5. High pressure mercury vapour lamp The electrons move toward the positive terminal and positive ions move toward the negative terminal, collision between moving ions and neutral argon atom causes further ionization and a glow of discharge is produced. Also, sufficient heat is produced to vaporize the liquid mercury inside the tube . It consists of a U-shaped glass tube, filled with argon gas at a low pressure. Small amount of mercury is enclosed in the tube and the tube is sealed at both the ends. At the ends of the glass tube, electrodes are placed, enclosed in metal caps across which a high potential difference is applied 07-06-2020 [email protected] 5

6. Kromayers lamp It can be used in contact with the body tissues absorbed by the circulating water so there is no danger of burns . The Kromayer’s lamp is a water-cooled mercury vapour lamp which eliminates the danger of burn and absorbs infrared rays Kromayer’s lamp can also be used to treat sinuses or deep body cavities. Direct contact method can also be used as it minimizes the danger of burn 07-06-2020 [email protected] 6

7. Fluorescent tube : Each tube is about 120 cm long and is made up of a glass which allows long ultraviolet rays to pass. The inside of tube is coated with phosphor. The spectrum of each tube depends upon the type of phosphor coating. A low pressure arc is set up inside the tube by the process of ionization. Phosphor is used to absorb short wave ultraviolet rays and these are reemitted at longer wavelengths. Therakitin tunnel It is a semicylindricular framework in which four fluorescent tubes are mounted in its own reflector in such a way that an even irradiation of a patient is achieved Normally, fluorescent tubes with a spectrum of 280–400 nm are used PUVA Apparatus : Irradiation with UVA may be performed with fluorescent tubes which may be mounted in a vertical battery on a wall or on four sides of a box totally surrounding the patient. This form of ultraviolet rays are usually given for two hours after the patient has taken a photoactive drug such as Psoralen , 07-06-2020 [email protected] 7

8. Physiological effects of UVR Carcinogenesis Erythema Pigmentation Thickening of the epidermis: Desquamation Production of vitamin D Aging Antibiotic effect 07-06-2020 [email protected] 8

9. Indications Wounds : Acne vulgaris: Pressure sores Psoriasis Alopecia : Rickets : Counter-irritation effect : Psychological effect 07-06-2020 [email protected] 9

10. Contraindication Acute skin conditions Hypersensitivity to sunlight Deep X-ray or cobalt therapy : Skin grafting : Porpyria Sarcoidosis Herplex simplex Xeroderma pigmentosum 07-06-2020 [email protected] 10

11. Dangers 07-06-2020 [email protected] 11

12. THANK YOU 07-06-2020 [email protected] 12