1. INFRARED RADIATION THERAPY 1

2.  Infrared are electromagnetic waves.  It lies b/w visible light and microwaves.  WAVE LENGTH: 750nm to 400000nm.  FREQUENCY: 4×10 Hz and 7.5×10 Hz.  NEAR OR SHORT IRR : 760 TO 1500nm.  FAR OR LONG IRR: 1500 TO 15000nm.  TYPES OF INFRARED RADIATIONS: 2

3.  ARRANGEMENT OF LAMP AND PATIENT:  The lamp is positioned opposite to the treatment area such that rays strike the skin at right angle.  Set the lamp at an appropriate distance which is usually 50-75cm  ABSORPTION OF INFRA-RED:  Some radiation striking the surface of skin will be reflected and some will penetrate scaterred, refracted and ultimately absorbed.  95% of the radiation applied perpendicular to skin is absorbed.  Water and protein are strong absorber of infrared.  Any radiation enter in skin depends on structure, vascularity, pigmentation and wave length of radiation.  PENTRATION OF INFRA-RED:  IR produce by luminous generator can pentrate into dermis and epidermis.  IR produced by non luminous generator can pentrate the superficial skin.  Pentration of energy into a medium depends on intensity of IR, wave length and frequency, angle, coffecient of absorption. 3

4.  PHYSIOLOGICAL EFFECTS:  Increase metabollic rate.  Cutaneous vasodilation.  Sweating.  Stimulation of thermal heat receptor.  THERAPUTIC EFFECTS:  Relief of pain.  Muscle relaxation.  Increased blood supply.  Increase joint mobility.  Healing and repair. 4

5.  DANGERS OF IR  Burns.  Electric shock.  Faintness  Headache.  Gangrene  Injury to eyes.  Dehydration.  CONTRAINDICATI ONS:  Defective arterial blood supply.  Haemorrhage.  Over pelvic region during pregnancy.  Varicose vein.  Tumors.  Directly over eyes.  Defective skin sensation. 5

6. Objectives  Following completion of this lecture the student must be able to;  Understand how the infrared radiation is classified in the electromagnetic spectrum.  Describe the physiological effect of infrared radiation.  Describe the indications and contraindications of infrared radiation.  Explain how the therapist can use the infrared radiation. 6

7. Outlines  Definition and classification (types).  Sources and production.  Physiological and therapeutic effects.  Indications and contraindications.  Dangers/Precautions  Practical and clinical application 7

8. Introduction  Infrared- Below red  Discovered by William Herschel in early 19th Century.  Two types: Near(Short) and Far (Long).  Near: not hot buy Far: Heat  IR wavelength: 710nm to 1mm.  Use: Remote control, radiant heater, grills, optical fibers, night vision.  Dangers: Skin burn. 8

9. What is Infrared ?  Infrared radiations are part of an electromagnetic spectrum, with wavelength of 750nm-1mm, and frequency of 4x1014 and 7.4x 1011, and located between microwave and visible light.  Infrared Radiations Infrared rays are electromagnetic waves with wavelengths of 750 to 4,00,000 nm. Any hot body emits infrared rays. For example the sun, gas fires, coal fires, electric fires, hot water, etc.  Infrared is superficial Heating modality (penetration depth 1- 10mm).  Infrared is radiant heat transmits energy by radiation. 9

10. Infrared Radiations  Infrared radiations (IRR) are electromagnetic radiation that lies within that part of electromagnetic spectrum between visible light and microwave radiation.  The radiation is characterized by wavelength extended from 760 nm to 1 mm.  IRR can be subdivided into 3 regions (A,B &C) according to their absorption and their effect upon the tissue. 10

11. 760nm to 1 mm 11

12. Production of Infrared  Infrared is produced as a result of molecular motion within heated materials. All hot bodies emit IR, as increase the temperature of any material above absolute zero result in vibration and rotation of molecule within the material.  The wavelength of the emitted IR are determined by the temperature of the material. The higher the temperature of the body, the higher the frequency, and the shorter the wavelength.  12

13. Sources of Infrared  Natural sources  The sun  Artificial sources:  1- Luminous sources  2- Non-luminous sources 13

14. Classification IR Classificat ion IRp Near (short)=750- 1500nm Far (long)=1500- 15000nm TypesIRA=750-1400nmIRB=1400-3000, IRC=3000nm-1m SourceLuminous heated body -Incandescent bodies -Sun -Tungsten Non-luminous Heated bodies -Hot pack -Electrical heating pads Penetrati on Deeper; penetratesto epidermis, dermis & subcutaneous (5-10mm) Superficial; penetratesto the epidermis ≤5mm Absorptio n DeepSuperficial 14

15. Luminous versus non-luminous IR 15

16. Classification of infrared radiation Penetration Wavelengt h Type 5 mm reach to dermis 760 - 1400 nm IRA(short or near IR) Up to 1 mm to epidermis 1400 – 3000 nm IRB(long or far IR) Not used therapeutically 3000nm – 1 mm IRC 16

17. Artificial sources  Luminous sources  Electrically heated filament made of tungsten filament within a glass bulb which contain an inert gas at low pressure. Part of the glass bulb is silvered to provide a reflector.  Luminous sources emit mainly:  - Short or near IR (IRA)  - Visible light  - Ultraviolet 17

18.  LUMINOUS GENERATOR:  Also known as high temperature generator.  Emits visible rays, ultraviolet rays and infra red rays of wave length 350nm to 4000nm.  Are in the form of incandescent bulb consist of a wire filament enclosed in a glass bulb which may contain inert gasses at low temperature.  Filament made up of tungsten it tolerates repeated heating and cooling.  Luminous generator is used for lesion of more chronic type. 18

19. Luminous(Visible) generator  Luminous generator are produced by INCANDESCENT LAMPS. This lamps consists of a TUNGSTEN FILAMENT which contain INERT GAS AT LOW PRESSURE. Inside of glass is silvered to provide reflection. When you pun on lamp it produces visible light, IR and few UVR. The radiation extends from FAR IR to UVR. Out side of glass is reddened, to absorb green and blue rays. Human skin absorbs 95% of energy if it is perpendicular to surface.  Emission : approximately 70 %(short IR)  5% Visible  24 % (long IR)  1% UVR absorbed by glass of bulb wadsworth and Chan mugan 1980 19

20. Non-Luminous  Non-luminous sources  Non-luminous sources are those which produce infrared radiation from a non-glowing source, such as moist heat packs and non- luminous IR lamps  Non-luminous infrared lamp consists of a coiled resistance wire which embedded within a ceramic insulating material  Non - luminous sources emit mainly  long or far IR radiation. 20

21.  TYPES OF IR LAMPS:  Luminous generators.  Non- luminous generator.  NON LUMINOUS GENERATOR:  Also known as low temperature generator.  Produce only infra-red rays of wave length 750nm to 15000nm.  These generator are heated by passage of electric current through a bare vire or carbon held in a non conducting material like procelain, mounted in the centre of parabolic reflector.  For recent injuries sedative effects of non luminous generator is more effective. 21

22. Non-Luminous  Non-Luminous and Luminous  Non-Luminous: A coil of wire wound on a cylinder of some insulating material. Electric current passes through wire and produces Heat. IRR emitted by hot wire. It produces IRR and Some visible rays. This kind of lamps required sometime to warm up, the lamp may take up to 15 mins to reach maximum emission.  Emission : mainly 3000-4000nm(long IR) with about 10% between 1500 nm and visible (short IR) 22

23. Depth of Penetration of Rays  Luminous generator produces infrared rays having wavelength between 350 to 4000 nm. It can penetrate into dermis and epidermis of the subcutaneous tissue. Nonluminous generator produces infrared rays of wavelength 750 to 15000 nm which can penetrate the superficial dermis only. The depth of the penetration depends upon the wavelength and the nature of the material (Fig. 5.2). Thus, infrared rays produced from a luminous generator have more penetration power than that produced from nonluminous generator. 23

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26. Factors Regulating Absorption & Penetration of IRR  Infrared radiations striking the surface of the skin will be reflected, scattered, refracted, penetrate and absorbed in the tissues. The depth of penetration and absorption of IR depends on; IRR is strongly absorbed near the skin surface and the heat is carried to deeper tissues by conduction and by the circulating fluids.  The absorption and penetration of IRR rays depend on:  1-Wavelength/ frequency of radiation  2-Thermal conductivity of the tissue  3-Thicknessof tissue.  4-Cosine law.  5-Inverse square law.  6Arndt-Schultsz principle  7-Grotthous Draper law 26

27.  8-Intensity of IR source.  9-Vascularity of tissues  10-Types of the skin  11-Wavelength of the rays  12 Angle of incidence of the rays.  13 -The intensity of the emitting source.  14 -The distance of the radiating source from the tissue. 27

28. 28  Arndt-Schultz principle: It states that no reaction or changes can occur in the body tissues if the amount of energy absorbed is insufficient to stimulate the absorbing tissues. Addition of threshold energy and above quantity of energy will stimulate the absorbing tissue to normal function and if too great a quantity of energy is absorbed then added energy will prevent normal function or will destroy tissue.  Law of Grothus-Drapper: It states that the rays must be absorbed to produce the effect and the effects will be produced at that point at which the rays are absorbed.  Cosine law: It is also known as Lambert-Cosine law. Cosine law explains the effect of angle at which the rays strike. It states that the proportion of rays absorbed varies as per the cosine of the angle between the incident and them normal. Thus larger the angle at which the rays strike at the body surface, lesser will be the absorption and vice versa. If the rays strike at 90º to the body part, then angle between the incident and normal are perpendicular will be zero and the cosine of 0º is maximum, i.e. 1. Thus there will be maximum absorption if the rays that will strike the body part at 90º as per this law.  Law of inverse square: Law of Inverse Square explains the effect of distance on the intensity of infrared 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.

29. Physiological Effects of IRR  Vasodilatation starts after 1–2 minutes and lasts for 30 minutes. Erythema: is of irregular patchy red appearance of skin (lasts for about 30 minutes) after IR application.  INCREASE 29

30. Physiological Effects of Infrared  IRR is considered as superficial heating modality  Cutaneous vasodilatation  Increase metabolism  Neurological effect (Pain control)  Effect on connective tissue 30

31. 1- Cutaneous vasodilatation  Heating with IRR leads to vasodilatation of the blood vessels as a result of:  release of chemical mediator histamine like substance  axon reflex mechanism.  Vasodilatation causes increase blood flow in the cutaneous circulation 31

32.  Vasodilatation starts after short period of exposure to IRR and leads to redness of the skin that appears as irregular patchy erythema and its intensity depends on the degree of heating.  This local erythema appears immediately after exposure to IRR and lasts 30 minutes after treatment has stopped. 32

33. 2-Increase metabolism  Increase temperature by IRR leads to increase metabolic activities within the superficial tissue due to direct effect of heat on chemical process in the cell  Increase metabolic activities lead to improve cell function and improve tissue healing. 33

34. 3- Neurological effect  The heat production by IRR leads to relief pain by:  Stimulation of sensory nerves (A-Beta nerve fibers) lead to inhibition of pain at the level of the spinal cord.  Decrease activity of muscle spindle leading to relaxation of muscle  Removal of waste products as the result of improving circulation and increase venous return thus removing the source of pain stimulation. 34

35. Effect on connective tissue  The heat effect of IR leads to increase the extensibility of connective tissue and therefore is used prior to exercise to increase range of motion (stretching and mobilization exercises).  N.B.  Increasing tissue extensibility by heating through IRR will not decrease soft tissue shortening. So infrared must be used in conjunction with stretching and ROM exercises. 35

36. Therapeutic Effects and Uses  Relief of pain & muscle spasm.  Mild heating has a 'sedatory' effect on sensory nerves endings used for the relief of acute pain.  Strong heating has a ‘counterirritant‘ effect on sensory nerves endings and used for the relief of chronic pain.  Joint stiffness: decrease, increase collagen viscosity extensibility  Skin lesion: psoriasis  Prior to other Treatments: (e.g. stretching, mobilization, traction, massage, exercise therapy, electricalstimulation, and biofeedback).  Increased blood flow and circulation (e.g. reduce chronic edema)  Muscles relaxation  Increase healing of tissue (no more recommended) 36

37. Therapeutic uses of IR  Relief of Pain  –When mild heating pain relief is due to sedative effect on superficial nerves  –Strong heating irritates the superficial sensory nerve relives pain by counter irritant  –Acute condition pain relief by mild heating  –In chronic condition pain relief by intense heating  Muscle Relaxation  –IR relax muscle by warmth and heating  –This relives muscle spasm and induce relief of pain  –Some time given before exercises  Increase blood supply  –It helps to increase the blood supply so help in superficial wound, infection  –Also increases WBC and remove waste products  –It is used to arthritis joints, other inflammatory conditions and after the effect of injuries 37

38.  Pain  Muscle spasm  Incisional wound (Acceleration of healing)  Subacute and chronic inflammation of musculoskeletal system  Chronic mild to moderate edema  Prior to stretching &mobilizing exercises  Some skin conditions (fungal infection)  Pain and Muscle spasm  Chronic inflammatory stage – oedema  Pressure sore, Healing of wounds  Joint stiffness- acute and chronic stage  Treatment of the patient’s condition:  1. Low backache  2. Postimmobilization stiffness  3. Edema. Therapeutic Uses of InfraredIndications 38

39. 39 Contraindications and Precautions  Acute inflammatory conditions  Impaired cutaneous thermal sensation and circulation  Peripheral vascular disease  Markedly loss of consciousness.  Acute skin disease, e.g., dermatitis or eczema  Deep X-ray therapy  Defective blood pressure regulation  Acute febrile illness (Fever)  Tumors of the skin  Hemophilia.  Acute inflammation  Acute infection  Open wounds  Impaired sensation  Impaired circulation  Over pregnant uterus  Eyes  Metal  Precautions  Unreliable and elderly patients.  Never apply heat directly to eyes or the genitals.  Never heat the abdomen during pregnancy (first and last trimester )

40. Dangers side effects of IR  Burn  Intensity of radiation is so high  Loss of sensation,  Reduce consciousness  Unreliable patients  Accidentally touch of hot element  Metal & Inflammable materials in treated area,  These dangers can be avoided by:  Follow application principle  Adequate warnings to the patient  Checking the skin several times  Dehydration  Lowering blood pressure &fainting Damage to the eyes  Electrical shock 40

41. Hazards and Dangers  Burns: The main danger of IR treatment is the burn. It occurs if  1- heat is too intense.  2- the patient is not fully aware of the level of heating.  3-the patient is unable to communicate with physiotherapist.  Eye damage : The eye should be covered with a light towel or head turned away during the application of IRR to avoid eye surface dryness or possible irritation. 41

42. Advantages vs. disadvantage  Can be used to treat large area, with local effect  Easy of application (Patients can apply at home)  Inexpensive  Heating only superficial tissue, therefore limited in use.  Not effective as hot packs and paraffin wax  Equipment is often unstable Advantages Disadvantages 42

43. Practical and clinical application Tips for Clinical application Select equipments Luminous Non-luminous Warm up Luminous-No warm up Non-luminous –warm up 15minutes Patients Indication/Contraindications Positioning /sensation Lamp positioning 40-90cmm Dosage Follow-up 43

44. Practical and clinical application  Selection of equipment:  Sedative effects- non-luminous IRR  Counter irritant(Chronic condition) – Luminous IRR  Setting up the lamp:  Never position the lamp over patient  Lamp must be placed perpendicular to area to be treated  Distance should be 50cm to 75 cm  Protect the eyes  Check the knobs and screw of the lamp  Switch on the heating element 44

45. Practical and clinical application  Clean the treated area from any sweat, dirt, or oils, and remove any jewelry.  Position the patient in a comfortable manner.  Drape the body part so that only the area to be treated is exposed.  If a moist heat treatment is desired, place a damp terry cloth towel over the area.  To prevent burns, instruct the patient not to move/sleep and  check the patients comfort periodically.  The intensity may be adjusted by moving the lamp toward the skin (increasing temp) or away from the skin (decreasing temp). [50-90cm]  After 5-10 minutes the vasodilatation has occur then the radiation can be increased  Instruct the patient to summon assistance if the intensity of the treatment becomes too great.  Treatment duration will be 15-30 minutes, 45

46. Tunnel Bath Method  It is used for several surfaces of part to be treated.  Temperature increases rapidly.  Specially used for Chronic condition. 46

47.  Mode of Heat transfer  Radiation Convection and conduction  NOTE:  IRA- Dermis and Subcutaneous level  IRB- Epidermis level  It is useful for heating superficial large areas  Intensity varies inversely with square of the distance from the lamp  It’s a dry heat compared to WAX and HOTPACK 47

48.  Placement of Infrared Lamp  Place the lamp at about 1-2 feet away from the treatment area so that rays are at right angles in order to achieve maximal penetration. Record the distance between the lamp and the treatment area.  Duration: Acute condition — 10 to 15 minutes  Subacute condition — 15 to 20 minutes  Chronic condition — 20 to 30 minutes.  INFRARED RADIATION FOR PSORIASIS  The increased temperature of the upper epidermis and the dermis in the region of psoriatic plaques produced by IR radiation has been proposed as the mechanism for the reduction in psoriatic plaques that occurs in some individuals exposed to IR radiation. 48

49. METHODS OF TREATMENT  Proforma for the Assessment of Patient  Treatment of the patient’s condition:  1. Low backache  2. Postimmobilization stiffness  3. Edema. 49

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52. Infrared irradiation  Infrared irradiation is a superficial, thermal agent use for the relief of pain and stiffness, to increasing and to enhance the healing of soft tissue lesions and skin editions (Kitchen and Partridge, 1991; Lehmann and de Lateur. 1999; Michlovitz,  Physical characteristics  Infrared (IR) radiations lie within that part of the electromagnetic spectrum which gives rise to heating when absorbed by matter (see fig. 1.20). The radiations are characterized by wavelengths of 0.76- 1000 um, which are between those of microwaves and visible light. Many sources which emit visible light or ultraviolet (UV) radi­ation also emit IR. The International Commission on Illumination (CIE) describes infrared irradiation in terms of three biologically significant bands, which differ in the degree to whir they are absorbed by biological tissues and therefore their effect upon those tissues:  IRA: spectral values of 0.78-1.4um  IRBP: spectral values of 1 4-3.0 um  IRC: spectral values of 3.0-1.O mm  The wavelengths mainly used in clinical practice are those between 0.7um and 1.5 um, and are therefore concentrated in the IRA band. 52

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