IRR.ppt

Infra-radio red ray

1. OBJECTIVES
After completing the lesson the student will be able to:
•To describe the physical properties of infrared rays,
ultraviolet rays and light amplification by stimulated
emission of radiation.
•To describe the therapeutic and physiological effects.
•To describe the methods of application.
•To list out the indications, contraindications and
precautions.
•To list out the adverse effects.

2. DEFINITION
•Infra-redraysareelectromagneticwaveswithwave
lengthof750to4,00000nm.
•Infra-redraysmaybealsocalledasthermiogenicrays.

3. CLASSIFICATION
•Based on wavelength infra-red rays are classified into:
•Short wave infra-red:
•Wave length –750 to 1500nm.
•Long wave infra-red (far infra-red rays):
•Infra-red A-wavelength –750 to 1400nm.
•Infra-red B-wavelength –1400 to 3000nm.
•Infra-red C-wavelength –3000nm to 1nm.

4. PRODUCTION
•Anybodywithhightemperaturethanthesurrounding
canemitinfra-redrays.
•ThenaturalsourceofIRRisthesun.

5. TYPES OF IRR USED IN PT
•The IRR generators used in physiotherapy can be
divided into two types:
•Non-luminous generator.
•Luminous generator.

6. Non-luminous generator

7. Luminous generator

8. DEPTH OF PENETRATION
•MaximumeffectivepenetrationofIRRis3mms.
•Luminousgeneratorshavebetterpenetrationeffectthan
thenon-luminous.

9. Laws regulating the absorption of
radiations
•Grothuslaw/Grothus-Drapperlaw:
•Thelawstatesthattheraysmustbeabsorbedto
producetheeffectandtheeffectwillproduceatthat
pointatwhichtheraysareabsorbed.

10. Law of inverse square:
•Law of inverse square explains the effect of distance on
the intensity of infra-red rays.
•It states that the intensity of a beam of rays from a point
source is inversely proportional to the square of the
distance from the source.

11. Law of inverse square
Theinversesquarelawtellsisthattheilluminationisinverselyproportionaltothe
squareofthedistancebetweenthepointsourceandthesurface,i.e.:
Ifyouhaveafixture(whichcanbetreatedasapointsourceifthedistancefromthe
surfaceislarge)andyoumeasuretheilluminationat20feetas2000Fcatthebeam
center,thenat40feettheilluminationis500Fcatthebeamcenter.

12. Cosine law / Lambert’s cosine law:
•Cosinelawexplainstheeffectofangleatwhichtherays
strike.
•Itstatesthattheproportionofraysabsorbedvariesas
perthecosineoftheanglebetweenincidentandnormal.
•Largertheangleatwhichtheraysstriketothebody
surface,lesserwillbetheabsorptionandviceversa.

13. Effective illumination is proportional to the cosine of the angle of incidence of
the light on the surface (angle between the direction of the light and the
perpendicular to the surface)
Illumination at the O point on surfaces 1 and 2:
Here are a few cases:
When the surface is tilted by an angle of 30º, the illumination is reduced by a factor of 0.87
45º -0.71
60º -0.5

14. Beer-Lambert law:
•Degreeofabsorptiondependsonthewavelengthsof
radiationandnatureofabsorbingmaterials.

15. Beer-Lambert law
•GeneralBeer-Lambertlawisusuallywrittenas:A=abc,
whereAisthemeasuredabsorbance,aisawavelength-
dependentabsorptivitycoefficient,bisthecell-path
length,andcistheanalyteconcentration.

16. Kirchhoff’s law:
•It states that good radiators are good absorbers.

17. Wien’s law:
•Thislawstatesthatthewavelengthofmaximalemission
isinverselyproportionaltotheabsolutetemperatureof
thesourcesothathotterthesourceshorteristhe
wavelengthofemittedrays.

18. Hotter objects emit most of their radiation at shorter wavelengths; hence they will appear to be
bluer .
Cooler objects emit most of their radiation at longer wavelengths; hence they will appear to be
redder

19. Stefan-Boltzman law:
•Thislawstatesthattheoutputoftheinfra-redlampwill
dependonthetemperatureoftheelementandits
radiatingarea.

20. Stefan-Boltzman law
The Sefan-Boltzman law relates the total amount of radiation emitted by an object to it's temperature:
E=sT4
where:
E = total amount of radiation emitted by an object per square meter (Watts m-2)
s is a constant called the Stefan-Boltzman constant = 5.67 x 10-8 Watts m-2 K-4
T is the temperature of the object in K

21. Arndt-Schulz principle
•Additionofasubthresholdquantityofenergywillnot
causeademonstrablechange.
•Additionofthresholdandabovequantityofenergywill
stimulatetheabsorbingtissuetonormalfunction
•Iftoogreataquantityofenergyisabsorbedthenadded
energywillpreventnormalfunctionordestroytissue.

22. PHYSIOLOGICAL EFFECTS
•WhenIRRisappliedtothebody,theyareabsorbed,and
theelectromagneticenergyisconvertedintothermal
energy,producingheat.

23. Physiological effects contd:
•Localriseintemperature.
•Increasedactivityofsweatglands.
•Increasedmetabolism.
•Vasodilatation.
•Relaxationofmuscletissue.
•Extensiveirradiationmayevencauseageneralrisein
bodytemperatureandfallinbloodpressure.

24. THERAPEUTIC EFFECTS
•Analgesia.
•Relief of pain.
•Muscle relaxation.
•Increased blood supply.
•Relaxation of muscle spasm.

25. INDICATIONS
•Subacuteandchronicinflammation.
•Osteoarthritis.
•Rheumatoidarthritis.
•Inflammatoryconditionsoftheskinfolliculitis,furunculitis.
•Priortostretching.
•Bell’spalsy.
•Musclespasmoforthopedicorigin.

26. CONTRAINDICATIONS
•Fever.
•Pelvic region in pregnancy.
•Malignancy.
•Impaired sensations.
•Anesthetic area.
•Advanced cardiac disease.
•Eczema.

27. •Dermatitis.
•Impaired circulation.
•Noninflammatory edema.
•Altered consciousness.
•Hemorrhagic conditions.
•Varicose veins.
•X-ray therapy.
•Extremes of age.

28. DOSIMETRY
•Acute cases –10 to 15mins. daily for 1 to 3 times.
•Chronic cases –30mins. Ones daily or on alternate
days.

29. PRECAUTIONS
•Covertheface,eyesandhairduringirradiation.
•Eyesshouldbeprotectedbymoistcottonpacksor
gogglestoavoidopacitiesoflens.
•ChecktheIRRgeneratortoensuresafety.

30. EQUIPMENT POSITIONING
•Arrange it in such a way that it is opposite to the center
of the area to be treated and the rays strike at right
angles.
•A distance of 50 –75cm has to be maintained between
the source and the treatment area.

32. HAZARDS
•Burns / blisters.
•Electric shock.
•Edema.
•Overdose.
•Faintness.
•Headache.
•Permanent pigmentation of eyes.