2 InfraredInfrared lamps emits electromagnetic radiation within frequency range heat absorbed by the matter.IR is emitted by many sources (e.g. the sun).
3 Physical Characteristics IR radiation has wave length of 770 nm to 1 mm.Part of EM spectrum lying between visible light and microwave.Divided into 3 bands:1- IR-A: 770 to 1400 nm2- IR-B: 1400 to 3000 nm3- IR-C: 3000 to 106
4 Types of IR radiation (Used clinically) Luminous (visible)Non luminous (invisible)IR lamps available emit radiation of wave length 780 and 1500 nm.
5 Physical Behavior of IRR: ReflectedAbsorbedTransmittedRefractedDiffracted
6 Physiological Effects of IRR: Metabolic effect:Increases metabolic activity.Circular effect:Increases blood flow superficially.Neurological effects:Increases nerve conduction velocity.Cellular effects:Increases elastic fibers in upper dermis.Increases ground substance.Alters composition of amino acid proteins.
7 Clinical (Therapeutic) Effects of IRR: PainMuscle spasmJoint stiffnessTissue healingCirculationEdemaSkin lesionOthers: before stretching, mobilization, traction, massage, exercises, E.S. , bile pigments.
8 Modes of Heat Transfer Dosage Radiation (lamp to body)Convection and conduction ( through the body)DosageSensory report of the patientِAdjusted by:Changing power output of the lampDistance of lampAngle of incidence
10 Microwave E.M.R. between the radio waves and infrared. Wavelength between 1 m and 1 cm.Frequency between 30MHz – 30GHz.Available since 1930Effective method of heating (highly vascular tissue)
11 Production of M.W. High frequency oscillating current. Magnetron to generate oscillating currents directly from high velocity electron motion.Coaxial cable.Antenna (emitter).Intensity control.Meter mean of switching.Can be continuous or pulsed.
12 Ultraviolet Radiations Physical properties of U.V. radiations:Electromagnetic radiations.Frequency 7.5x1014 to over 1015.Wavelength 400nm to below 290nm.Lies between x-ray and visible light.Divided into three bands, A, B and C band.A and B bands reach the earth, whereas C band is filtered by the ozone layerProduce physiological effect by non thermal mechanism
13 Most significant source of U.V. is the sun. Obeys inverse square and cosine law.Intensity is proportional to the power of lamp output.Deepest penetration with high intensity, long wavelength and lower frequency.U.V.A penetrate farthestU.V.B and U.V.C are less deep.Less deep penetration if skin is thick or dark.
14 Physiological Effects of U.V.R 1- Erythema production:Redness.Depends on the amount of U.V.Types of erythema.High dose destructive.
15 Delayed pigmentation of the skin 2- Tanning:Delayed pigmentation of the skinCaused by:Increase production and upward migration of melanin granulesOxidation of premelanin in the skinProtective response of the body
16 3- Epidermal hyperplasia Thickening of the superficial layer of skin.72 hours after exposure.Persists for several weeks.Protective mechanism.4- Vitamin D SynthesisConversion of provitamin D to vitamin D.5- Other EffectsBactericidal effect.
17 Erythemal Respons Suberythemal dose (SED) : No change in 24h after exposure.Minimal erythema dose (MED) :Smallest dose erythema (8h)Dissapears within 24 hours
18 First-degree erythema (E1) : Definite redness with mild desquamation.Appears within 6 hours.Lasts for 1 – 3 daysAbout 2.5 times MEDSecond degree erythema (E2)Intense erythema with edema, peeling and pigmentation.Appears within 2 hours or less.Like severe sun burn.About 5 times MED.
19 Third degree erythema (E3) : Erythema with severe blistering, peeling and exudation.Dose about 10 times MED
20 Clinical Indications for U.V. radiation Skin disorderPsoriasis and other dermatological conditionsNon pulmonary T.B.Healing wounds
21 Application Technique Determine patient’s sensitivity to U.V radiationUse the same lampDose response assessmentGraded according to individual’s erythemal response