infrared rays for 3rd year bpt

8/13/2019 Infrared Rays for 3rd Year BPT

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Infrared radiations are produced in allmatter by various kinds of molecular

vibration.Any object emits infrared radiations and

material that is at temperature aboveabsolute zero emits infrared.

Infrared radiations gives rise to heatingwhen absorbed by matter.

Longer than visible red light extending tothe microwave region, i.e., from 760 nmto 1 mm.

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The frequencies of radiation isproportional to temperature. Thus thehigher the temperature the higher thefrequency and hence the shorter thewavelength.

The shorter, visible radiations not onlycause molecular and atomic motion butcan also break chemical bonds when theyare absorbed.

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1. Luminous and non-luminous.

2. Subdivided :- A, B, C

- (A and B ) utilized therapeutically

IRA - 760 nm to 1400 nm

IRB - 1400 nm to 3000 nm

IRC - 3000 nm to 1 mm

3. Former Classification

Near or Short IR - 760 nm to 1500 nm

Far or Long IR - 1500 nm to 15000 nm

Any heated material will produce infrared

radiations, the wavelength beingdetermined by the temperature.

The most convenient method is to heat aresistance wire by passing an electriccurrent through it.

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1. a coil of suitable resistance wire, wound ona ceramic insulator.(glows red)

2. wire embedded in the insulating ceramic sothat no visible radiations are given out.

3.The heater wire can also be mountedbehind a metal plate or inside a metal tube,

which does not become red-hot but emitsinfrared in the same way.

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When such lamps are switched on theyrequire some time to reach a stable, peak

level of heat emission as the molecularoscillation causing heating spreads slowlythrough the body of the heater.

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Consist of a tungsten filament in a large glassenvelope, which contains inert gas at low

pressure.

Oxidation of the filament does not occurbecause there is no oxygen present, only atrace of some inert gas.

The peak emission occurs at near 1000 nm butlong infrared ,visible rays and ultraviolet arealso produced. UVR are absorbed by the glassand are not therefore transmitted by the

lamp. Sometimes the glass is reddened, to give a red

visible emission.

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Large lamps are fitted with wire-meshscreens over the front of the reflector to

prevent accidental contact with the hotemitter. The screen will also diminish any

remote risk of the hot emitter elementfalling out.

Stand

Caster

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Non luminous:

Mainly 3000 4000 nm (long IR),

with about 10% between 1500 nm and visible(short IR)

Luminous:

Peak emission at 1000 nm and below

Approximately 70% short IR ,5% visible, 24%long IR, 1% UVR absorbed by glass of bulb

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Radiations striking the surface may be:

1. Reflected or

2. Transmitted : scattered, refracted, andultimately absorbed in the tissues.

Close to 95% of the radiation appliedperpendicular to the skin is absorbed.

Skin (epidermis & dermis) is nothomogeneous tissue but a complicatedmultilayered structure full of irregular forms,

such as hair follicles and sweat glands.

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Therefore, it is difficult to determinepattern of penetration and absorption of

infrared radiation in the skin. In general, water and proteins are strong

absorbers of infrared.

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The long infrared used therapeutically isabsorbed at the surface, much of it by the

water on the skin surface. Because the energy penetration decreases

exponentially with depth, most heatingdue to infrared will occur superficially.

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At around 3000 nm, penetrating depth isabout 0.1 mm.

From here there is increasing penetrationwith decreasing wavelengthin the shortinfrared region, to maximum penetrationdepth of about 3 mm around the 1000 nmwavelength region.

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Cutaneous Vasodilatation:

- As a consequence of heating with infraredradiations local cutaneous vasodilatationwill occur which leads to erythema.

- The local erythema lasts for about 30minutes after irradiation has stopped.

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Sweating:

With prolonged or intense heating,sweating will start to occur.

Sensation:

Thermal heat receptors will be stimulatedin the skin so that the patient is aware ofthe heating.

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Increase in Metabolism:

Due to increase in temperature there willbe an increase in the rate of metabolism.

Chronic Changes:

Excessive and prolonged infraredapplication can cause the destruction oferythrocytes, releasing pigments andcausing brown discoloration of the skin.

This rarely occurs as a sequel to normal

treatment; it usually results from prolongedexposure of the legs to domestic fires.

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Relief of Pain:

Mild heat has sedative effect on the

superficial sensory nerve endings. Stronger heating irritates the superficial

sensory nerve endings, and so relievespain by counter-irritation.

An increased flow of blood through thepart removes nociceptive substances andso relieves pain.

When pain is due to lesions of a more chronictype, stronger heating is required.

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Muscle Relaxation:

Muscles relax most readily when the tissues

are warm, and the relief of pain alsofacilitates relaxation.

Infrared radiation is thus of value inhelping to achieve muscular relaxationand for the relief of muscle spasmassociated with injury or inflammation.

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Increased Blood Supply:

This effect is most marked in the superficialtissues, and may be used in the treatment ofsuperficial wounds and infections.

Good blood supply is essential for healing totake place, and if there is infection theincreased number of white blood cellsand theincreased exudation of fluid are of assistancein destroying the bacteria.

Infrared treatment is frequently used forarthritic joints and other inflammatorylesions, and for the after-effects of injuries.

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Pressure Sores:

Infrared has also been suggested for the

prophylaxisof pressure sores, to promotea greater blood flow in the skin.

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Oedema:

Infrared is sometimesused for surfaceheating of a part in elevation in order tohasten reabsorption of oedema.

This effect is limitedbecause infrared heatsthe superficial tissues and because it is

usually only applied to one aspect at a time.

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Prior to other Treatments:

Infrared is sometimes chosen as a form ofheat prior to stretching, mobilization,traction, massage and exercise therapy.

It may also be used prior to electricalstimulation to warm the skin, making it

more vascular and hence a better conductor.This is done before wetting the skin to lowerits electrical resistance further.

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Burns:

defective sensation or reduced

consciousness.mentally retarded.

Occasionally patients accidentally touch thehot element if there is no protective guard.

These dangers can be avoided by:

Careful application

Adequate warnings to the patient

Checking the effects on the skin severaltimes during the application

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Skin Irritation:

Some chemical irritants on the skin have

their effects increased by heating sometimesto the point of irritation or inflammation.

For this reason liniments should be removedprior to treatment.

Eye Damage:

Long-term irradiation can cause corneal andretinal damage leading to cataract.

Protect eyes form irradiation.

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Lowered Blood Pressure:

As infrared treatment causes marked

cutaneous vasodilatation it may lead totemporary lowering of blood pressure,particularly in elderly people who have less

effective vasomotor control.

This may lead tofaintnessespecially onstanding up immediately after treatment. It

may also cause headache.

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Areas of Defective Arterial Blood Flow:

Areas in which the arteries and arterioles

cannot respond by adequate vasodilatationto the demands of additional heating shouldnot be treated(atherosclerosis, arterialinjury or after skin grafting).

The possible result of heating such tissuewould be tissue necrosis (gangrene).

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Impaired cutaneous thermal sensation

Defective arterial cutaneous circulation Patients whose level of consciousness is markedly

lowered by drugs or diseaseAcute skin disease, e.g., dermatitis or eczema Skin damage due to deep X-ray therapy or other

ionizing radiation Defective blood pressure regulationAcute febrile illness additional heating is not

helpful and possibly dangerous to patients whoseheat regulation system is under stress.

Tumours of the skin may be stimulated to increasegrowth

Testes Subjects with advanced cardiovascular disease

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THANK YOU

Dr.Mittul Patel

infrared rays for 3rd year bpt

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