infra red radiations

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InfraRed Radiations

Infra Red RadiationsPresented by:Sidra Aslam AnsariSania ShaukatShaista GhazalAnokhi RaniSaeeda Shafiq

210/20/2014Topics:IntroductionProductionClassification Physical EffectsPhysiological EffectsIndication and contraindicationsDangersTechniques of application

310/20/2014Introduction:Infra red rays are electromagnetic waves.

Having wavelength of 750nm-400000nm 410/20/2014

510/20/2014Classification of IRR:IRR are also classified according to their distance from the visible spectrum as:

Near or short IRR: Having a wavelength from 770-1500nm10/20/20146Classification of IRR: Far or Long IRR: Having a wavelength from 1500-12,000nm

10/20/20147Production Of IRR:Any Object having a temperature above that of absolute zero emit infra red raysThe sunGas fires Coal firesElectric firesHot Water pipes810/20/2014Production of IRR:For use in physiotherapy two types of infra red lamps are used

Luminous Infra red

Non-luminous Infra red910/20/2014Luminous Infra Red: Luminous generator emits IRR

Rays emitted from luminous generators are produced by one or more incandescent lamps.1010/20/2014Luminous Infra Red:An incandescent lamp consists of a wire

filament enclosed in a glass bulb, which may

be evacuated or may contain an innert glass

at low pressure

1110/20/2014Luminous Infra Red:The filament is a coil of fine wire and is

usually made of tungston ; as this material

tolerates related heating and cooling.1210/20/2014Luminous Infra Red:The passage of an electric current through

the filament produces heat, Infra red, visible

and few Ultra violet rays.

1310/20/2014The spectrum is from 350-4000nm

The greatest proportion of the rays having

the wavelength the region of 1000nm

1410/20/2014Non-Luminous IRR:An electric current is passed through resistance wire covered with copper tubing or with clay; generate non-luminous IRR.10/20/201415Physical Effects of IRR:1610/20/2014Physical Effects of IRR:IRR obey the law of electromagnetic radiation such as: ReflectionRefractionAbsorptionLaw of inverse square 1710/20/2014Physical effects if IRR: Heat Production:

IRR produce heat in the tissues in which they are absorbed.

10/20/201418Heat production:Short/luminous IRR having a frequency

range of 700-1500nm will produce heat.

10/20/201419Heat production:It can penetrate upto the dermis and superficial sub-cutaneous tissues.

Long/non-luminous IRR having a frequency range of 1500-12000nm can penetrate to about 2mm that is upto the superficial dermis.10/20/201420Heat Production:Degree of temperature:

There is generally a 1-2 degree rise in temperature.

10/20/201421Heat Production:The degree of elevation of heat depends on:

The ability of tissues to absorb heat

The specific heat of tissues

Thickness of tissues.10/20/201422Absorption of IRR:The absorption of IRR depends upon:

The frequency or wavelength

Angle of incidence from source

Distance of source

10/20/201423Frequency or wavelength:IRR with a wavelength of longer than 3000nm are totally absorbed by the moisture present in the skin.

Both the long and short IRR are absorbed by the moisture present in the skin, thus reducing the absorption of heat.10/20/20142411% of the short/luminous IRR are absorbed by the glass of the bulb33% is reflected from the skin56% is absorbed of the 56% absorbed rays 36% is absorbed in the epidermis, 10% goes deeper into the dermis and remaining is scattered in the epidermis. 10/20/201425The long IRR; 36% is reflected 20% is absorbed in superficial dermis16% reaches the deep epidermis19% penetrate upto dermis11% is absorbed by the glass of bulb10/20/201426Absorption of IRR:Angle of incidence from the source:

According to Lamberts Cosine Law, the angle of incident determines the amount of radiation absorption.10/20/201427Absorption of IRR:Absorption at 90 of incident ray is maximum due to zero reflection.

As the angle of incidence from the source to surface increases, the reflection also increases and so is the absorption decreases.10/20/201428Absorption of IRR:For every 15 increase in the angle of incident on the surface, the absorption decreases by 3%.10/20/20142929The Distance Of Source:Obey inverse square law; the intensity of radiation varies with square of distance.

i.e, if the radiating source is moved to half the distance nearer or further, the intensity increases four times or decreases four times.10/20/201430Absorption of IRR:The absorption of IRR also depends on the:

Thermal conductivity of tissue, Density of tissue, Specific heat of tissue Circulation of the tissues.10/20/201431 Physiological Effects Of IRR10/20/201432Physiological effects: Infra red rays have an immediate effect of producing heat in the tissues when absorbed. All physiological effects obtained are due to rise in temperature (heat) in the tissue.

10/20/201433Physiological effects:There are nine physiological effects which I am discussing in my topic.


10/20/2014351-The superficial blood vessels dilate because of the direct effect of heat.

2- Heat causes liberation of histamine like substance which act on the capillaries and cause them to dilate.

VASODILATION:3- Heat regulatory centre in the medulla also signals the capillaries to dilate as the temperature rises.


Nerve stimulation:10/20/201437Heat stimulates the sensory nerves , perhaps the rise of temperature decrease gamma fiber activitydecreases paindecreases muscle spasm and promote relaxation

Nerve stimulation:An increase in temperature to 43C produces vasodepression of vasomotor reflex, causing release of vasoactive agents10/20/201438Increase temperature causes increased phagocytotic effects promoting healing of superficial wounds

Also in suppurating conditions such as carbuncles and abcess heat can help in drainage.

10/20/201439Phagocytosis:Pigmentation and Erythema:Erythema caused by the irradiation of infra red rays disappears readily, soon after the heating has stopped10/20/201440Pigmentation and Erythema:Repeated exposures with infra red rays can cause pigmentation of the skin because of the destruction of blood corpuscles and is known as erythema abigne10/20/201441

Decreased Blood Pressure:When infra red rays are given to larger areas for prolonged periods , fall in blood pressure results due to generalized vasodilationIt causes decreased peripheral resistance to blood flow. Local application however, does not affect the blood pressure10/20/201442Effects On Metabolism:According to Vant Hoff Law, for every 10 increase in temperature there is two-three fold increase rate of cellular oxidation.

10/20/201443HEATAlso increased extensibility of the collagen tissueDECREASED MUSCLE SPASM:Muscle spasm is reduced due to decreased firing of secondary afferents of muscle spindle and increased firing of 1b GTO fibers reducing alpha10/20/201444Pain ReliefHeat causes pre-synaptic inhibition of A delta and C fibers via activation of A-beta fibers.Actual phenomenon for pain reduction is not fully reabsorbed.

10/20/201445Pain relief:It is thought also that raised temperature of the tissue decreases the gamma activity.

10/20/201446 Indications and Contra-indications10/20/201447Indications Of IRR:Painful Conditions:

Both Luminous and non-luminous IRR are used to relieve pain and muscle spasm

10/20/201448Indications Of IRR:Oedema:

IRRs help in absorption of exudates because of capillary dilation

10/20/201449Indications Of IRR:Healing of Wounds:

Wound healing following IRR is due to the vasodilation effect.

IRR also help in drainage of wounds and sinuses.10/20/201450Skin Conditions: Infra red radiation make dermatomal conditions worse such as dermatitis( A condition in which skin become red & swollen resulting from irritation of skin by an allergic reaction.Eczema

10/20/20145151 Direct exposure of eyes to infrared rays can cause cataract.(In which lens of the eye become progressively opaque resulting blurred vision)

10/20/201452Damage To Eyes: Heat will render the patients perception of rise in temperature. This failure to detect excessive heat may result in burn.10/20/201453Loss Of Sensations:Deep X-ray Therapy:Following deep X-ray therapy Infrared rays should not be given for 3 months. Deep x-ray therapy also reduces the sensation over the exposed area. Thus may get burned10/20/201454 Patient On Strong Analgesics: Drugs have raised pain threshold,thus the patient will not be able to determine whether the intensity of heat is too much causing burn10/20/201455In Case of Skin Tumors: Heat tends to accelerate the growth of tumors. Patients with cardiac problems10/20/201456 Dangers Of IRR: BURN ELECTRICAL SHOCK 10/20/20145710/20/201458TECHNIQUES OF INFRA RED TREATMENTChoice of Apparatus:10/20/201459 Choose the modality i.e. LUMINOUS or NON LUMINOUS.

Apparatus should be in working order.

Pre-heated at least 5 minutes before heating.

Note the voltage of the emitter.

Usually lamps with emitters from 250 to 1000 watts are used.

10/20/201460Preparation of patient:Position of the patient should be comfortable and adequate.

Avoid undue movement of the patient.