What is Infra-red Radiation?

Infra-red radiation also denoted as IR is electromagnetic waves with a wavelength of 750 nm to 400,000nm. Any hot body emits IR rays: the sun, gas fires, coal fires, electric fires, hot water pipes, etc. Various types of IR generators are employed in the physiotherapy department, all designed to comply with DHSS regulations for IR.

Generators For IR production 

luminous generators

The  IR rays emitted from the luminous generators are produced by one or more incandescent lamps. An incandescent lamp consists of a wire filament made up of tungsten enclosed in a glass tube that contains inert gas at low temperatures. The passage of an electric current through the filament produces heat : infrared, visible, and a few ultra-violent rays are emitted. The spectrum is from 350 to 4000 nm. , the greatest proportion of rays having wave length in the region of 1000nm.

Nonluminous generator

A simple type of element for producing in IR rays consists of a coil of wire wound on a cylinder of some insulating material, such as fireclay or porcelain, rather like the element of a radiant electric fire. An electric current is passed through wire and produces heat. Some visible rays are produced as well as infrared, and when the element is hot a red glow is visible, so this type of element is not perfectly ‘non-luminous’. The reflector which is responsible for IR rays is mounted on a stand and its position can be adjusted as required.

 The wavelength is from 15000nm down to 750 nm or less if some visible rays are emitted. The maximum emission is in the region of 4000 nm.

Techniques of Infra-red Radiation (IR) treatment

1. Choice of apparatus

   Luminous generator – In lesion and chronic type

   Nonluminous generator – Acute inflammation condition

2. Preparation of patient
   • Remove clothing from the affected area
   • Test the skin sensation
   • He/she should not touch the lamp
   • The patient should be comfortable so he does not move during treatment.
3. Arrangement of lamp and patient
   • The IR should strike the skin at a right angle
   • Distance b/w lamp and patient –75 to 50 cm
   • The patient’s face should not be exposed, if the treatment is given then the eyes must be shielded with wet cotton and a tap.
   • IR is harmful to the eyes. 
4. Application of IR treatment
   • Exposure of 10 – 15 minutes
   • Vasodilation and increased blood flow then the strength of radiation may be increased.
   • Sweating during treatment ( rise in temp )
   • Exposure to  IR rays leads to redness.
5. Duration and frequency of treatment
   Acute inflammation – 10 to 15 min
   Chronic conditions—Longer exposure

Indication of Infra-red Radiation

Relief of pain

Pain is due to the accumulation of waste products of metabolism and an increase in blood flow removes these substances and relieves pain.

Muscle relaxation

The IR warms up tissue and helps to relief pain leading to muscle relaxation.

Increased blood supply

• During the healing process there is an increase in blood supply which helps to improve healing.
• During infection, there is an increased number of WBC and exudation fluid which destroy the bacteria as soon as they come in contact with IR.
• The IR treatment is used in arthritic joint, inflammatory lesions.

Contraindication of Infra-red Radiation

The IR can be harmful in various conditions such as ;

1. Defective arterial blood supply
2. Hemorrhage
3. Skin sensation

Danger of Infra-red Radiation

1. BURN
2. ELECTRIC SHOCK’
3. GANGRENE
4. HEADACHE
5. FAINTNESS
6. INJURIES