In The Name of GOD

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In The Name of GOD

• 87.5.18

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Deep Heat

• Dr M.N AHRARI
• (physiatrist)
• Kerman university of medical sciences

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Target tissue in diathermy

• Muscles
• Tendone
• Ligament
• Bone

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Therapeutic Target temperature

• 40-45 c

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Ultrasound-US

• Diagnostic use
• Therapeutic use
• Acoustic vibration with frequencygtaudible
  range(20,000Hz)

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US

• Reverse piezoelectric effect
• Quartz crystal
• Synthetic ceramics
• Thermal effects
• Non-thermal effect

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US as US waves travels through tissue,they lose
a proportion of their energyAttenuation

• absorption
• beam divergence
• deflection

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US-cont

• Absorption
• Increase Freqincrease absorptionincrease heat
• Beam divergence
• Beam spreads out from the transducer
• Increase frequency decrease beam divergence

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Beam Deflectionus

• Reflection
  
• Acoustic impedance between tissues
• A2-A1/A1A2
• Acoustic impressistance to transmission of a
  sound wave(velocity of sound,density of medium)
• Refraction(divertion of beam direction in tissue)
• Snells law sin1/sin2vel 1/vel2
• Scattering ---surface irregularrity
  

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US parameter

• Frequency 0.8-1 hz
• Power total energy in time unit
• Intensitypower per unit area
• Intensitypeak or average
• Intensityspatial ot temporal
• 0.5-2 W/cm2 WHO lt3 W/cm2 spatial average
  intensity
• US Pulsed or continuous
• Pulsed mode for increase non-thermal effect

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US Non-thermal effect

• Cavitation(Stable,Unstable)high
• High freq-low intensity-pulsed modedec
• Media motion(acoustic streaming,microstreaming)
• Standing Waves(focal heating)
• Strocking techniquedec

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Us precautions

• Near brain,eye,reproduce organ
• Gravid or mense uterus
• Near pacemaker
• Near laminectomy site
• Skeletal immaturity
• Malignancy
• ?athroplasty or metal

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Shortwave DiathermySWD

• Produce deep heating via conversion of
  electromagnetic energy to thermal energy
• Most common frequency used27.12 MHz

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SWD

• Heating pattern produced depends
• SWD Unit1.inductive (high water)
  2.capacitive(low water)
• Water content of tissue1.high water
  content(muscle,skin,blood)
• 2.Low water content(bone,skin)

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SWD Precautions

• Contact lens
• Metal(IUD,Pacemaker,jewelry)
• Skeletal immaturity
• Gravid or mense uterus

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Microwave diathermy(MWD)

• Produce deep heating via conversion of
  electromagnetic energy to thermal energy
• 915 MHz,2456 MHz
• 41 c in depth 1-3 cm
• Precautions US