microwave diathermy 2013

7/26/2019 Microwave Diathermy 2013

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is a means of producingtherapeutic heat byabsorption & conversion ofEM radiation in the

microwave band offrequencies


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Microwave diathermy (MWD), is a form of

electromagnetic radiations (part of electromagnetic

spectrum), lying between shortwave and infraredwaves !he microwaves diathermy gives super"cial

heating where energy is "rst absorbed at the

surface of the body (s#in) and a part of it penetrate

and absorbed in deep tissues


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Electromagnetic radiation which lies between the shortwaveand the infrared regions of the electromagnetic spectrum$requency of microwave is % ' % M

!he wavelength is * mm ' *m$requency and wavelength used for therapeutic purposes

+ - M is the frequency that is widely available fortherapeutic purposesE.ective penetration of it is about % mm/ut the lower frequencies have the ability to penetratemore

Frequency Wavelength2450 12.2

915 32.8

434 69.1


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SWDFrequencyof 27.12MHz andwavelengthof greaterthan 11 m

MWDFrequencie of2!"#$ %1" and

!&&.% MHz witha wavelengthof 122."$ &and '%# mmre (ectively


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SWDMachine

circuit

)(roduce HF*and am(lifyit inten ity+

,atientcircuit

MWDMagnetron )adiode valve that(roduce Hi-/*+0ran ducercircuit )with

antenna re ector+


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01 2ower 3witch/1!imer415utput Meter (indicates relative output in watts)

D1 2ower 5utput 6evel 7nobE1 0mber 6ight8Warming up 9 :ed 6ight8 :eady

8


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!hese currents are passed to theantenna that emits microwaves

!he antenna is a piece of wire thatis mounted in front of a metalre;ector which emits the waves inone direction5utput of the microwave energycan be controlled by varying thepower supply to the magnetron

!he frequency produced dependson the structure of the magnetronand it is therefore "


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!here are di.erent shapes of directors used inmicrowave applications=6arge circular "eld director= the e.ectivediameter is + mm !he heating pattern ismore intense around the outer portion thanthe centre !he power output range is up to+- watts


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3mall circular "eld director= the e.ectivediameter is * mm the heating pattern ismore intense around the outer portion than inthe center !he power output is up to +- watts


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6ongitudinal director= the e.ective treatmentarea is - mm by * mm the heatingpattern tends to be more concentrated in thecenter of this area !he power output is up to+- watts


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eat production in the tissues is theprominent e.ectWater containing tissues such as musclesabsorb more rays than the tissues li#e fat andbone3#in is heated up to a greater e of rays arere;ected from the air8s#in surface


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SWDElectrostati

c andElectro8

magnetic

MWDElectro8

magnetic


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SWDWater

contentspacing

si e of thecondenser

MWDwater

contentfrequenc

ydistance


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SWDdeep, up

to "# mmor " cm

MWDmore

super"cialthan 3WD,

up to &-!cm.


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Techniques of Application: MWD

3arge *ircular Small *ircular3ongitudinal

Diameter 200 mm 100 mm 500x100 mm

heating out > center outer > inner center > outerpattern

power 250 watts 25 watts 250 watts output


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2ainMuscle spasm4hronic in;ammation

Delayed healing4hronic infection$ibrosis


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Disorders of musculos#eletal conditions3prains3trains

4apsular lesionsDegenerative ?oint disease4hronic rheumatoid arthritis3ti.ness in super"cial ?ointsaematoma


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3uper"cial in;ammatory orinfective conditions

!enosynovitis/ursitis3ynovitis4arbuncles


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5ver malignant tissues5ver ischemic tissuesModerate and e


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Duration= + minutes is the most favorabletreatment time

@ntensity= 5nly safe measure is the sensation of

warmth described by the patient$requency of treatment= treatment may begiven daily or on alternative days @t is mostbene"cial if given once or twice daily


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Bariation in the applicationdepends on the si e andthe heating pattern of theemitter C director9transducer9applicator9radiator)


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!he patient should be positioned in wellcomfortable manner with adequatelye


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Emitter should be position to get a beamof radiation which stri#es the s#in at rightangles Emitter8 s#in distance is about +cm

!est the machine by placing the therapistshand under the director3witch on the machine after setting thetimer

@nstruct the patient to not to loo# at theapplicator and warn him regarding theburns


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3implicity of application and operation ofmachine0ccurate locali ation of heat

6ow frequency microwaves causesselective heating in musclesDeep structure cannot be heated@t can heat only one aspect of a ?oint3#in burns may develop rapidly

microwave diathermy 2013

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