Therapeutic Ultrasound

  1. Transverse Sound Waves
    • The molecules are displaces in a dricection perpendicular to the direction in which the wave is movin
    • can travel only in solids
    • found only when ultrasound strikes bone
  2. Frequency
    • The number of wave cycles complete per second
    • Increased frquency Increased focus of beam
  3. Frequency of therapeutic ultrasound
  4. Frequency vs penetration
    • 1MHz= 2-5cm of penetration
    • 3MHz= 1-2cm of penetration
  5. Attenuation
    • Attenuation is a decrease in energy intensity
    • As ultrasound traves through tissue there is a decrease in energy due to absorption dispersion scattering reflection and refraction
    • Absored in protein
    • Penetrates in Water
  6. Piezoelectric Effect
    • The Reverse piezoelectric effect is the production of mechanical energy by imposing electric charges across the crystal
    • The piexoelectric effect- the phenomenon of developing an electric charge on certain crystals by applying mechanical pressure to them
  7. ERA
    • the portion of the surface of the transducer that actually produces the sound wave is referred to as the effective radiating area
    • The size of the crystal
    • treatment area is 2-3time the ERA
  8. 1MHZ
    • Deep Heat
    • 2-5cm
    • Helpful in Pt with high percent of body fat
  9. 3MHz
    • superficial heat
    • 1-2cm
    • absorbs energy 3 times faster tah 1MHz
  10. BNR
    • Beam Nonunifomity Ratio
    • Beams are not homogeneous along thier longitudianl axis
    • BNR should be 2-6
    • The output can get higher than what you program the machine to be at
    • High BNR = move faster
  11. Continuous Ultrasound
    • The sound intensity (heat) remains constand throughout the treatment
    • 100%
  12. Pulsed Ultrasound
    • The inensity if periodically interruped
    • no energy being produced during the off period
    • Low % used during nontheramal or mechanial ultrasound
  13. Duty Cycle
    The Percentage of time that ultrasound is being generated (pulse duration) over one pulse period.
  14. Intensity of ultrasound
    • Degree change
    • A measure of the rate at which energy is being delivered per unit area
  15. Physiological Effects of Ultrasound
    • Increased rate of tissue repair and wound healing
    • Increased blood flow
    • Increased tissue extensibility
    • Breakdown of calcium deposits
    • reduction of pain and muscle spasm through alteration of nerve conduction velocities
    • change in cell membrain permeability
  16. Thermal Effects of Ultrasound
    • An increase in the extensibility of collagen fibers found in tendons and joint capules
    • Decrease in joint stiffness
    • Reducion of muscle spasm
    • Modulation of Pain
    • Increased blood flow
    • Mild Inflammatory respone that may help in the resolution of chronic inflammation
  17. Thermal Effect on collagen
    Collagen can be heated without heating the superficail heat
  18. Non Termal effects of ultrasound
    • Micomassage
    • Alters Membrain Permeability
    • Arteriolar vasoconstriction or dilation
    • Cavitation
    • Nonthermal effects of ultrasound maybe more important than thermal effects
  19. Micomassage
    • microscopic movement or oscillation of body fluids and tissues as a result of exposure to ultrasound
    • "cellular Massage"
    • Don't Feel this
  20. Altered membrane permeability
    • Acoustic microstreamin is the mechanism that induces changes in diffusion rates and membrane permeability
    • affects swelling
    • Keeps fluid in Vessels
  21. Arteriolar Vasoconstriction or Dilation
    Nontheram effect of arteriolar vasoconstriction or asodilation is not clear
  22. Cavitation
    Formation and collapse of gas or vapor filled cavities in liquids
  23. Blood Flow and Ultrasound
    • continuous ultrasound can increase local blood flow for up to 45 mins after treatment
    • these findings are not universally accepted
  24. Tissue Healing and Ultrasound
    • ultrasound application accelerates the inflammatory phase of tissue healing
    • macrophage activity
    • increases the adhesion of leukocytes to the damaged endothelial cells
  25. Tissue Stretching After Ultrasound
    • Have to 5 degree temp change in tissue
    • 3MHz - 3 mins after to have effective strethching
    • 1MHz - a little longer than 3 mins
    • Stretch right after ultrasound 1-3 min window
    • Stretch during ultrasound
  26. Pain Control of Ultrasound
    • elevates pain threshold (changes cell membrane permeability to sodium ions)
    • changes nerve conduction velocity
    • Counterirritand effect
  27. Advantages of Ultrasound
    • capable of producing significant temperature changes deep within the tissue
    • localized treatment
    • application times are short
  28. Disadvantages of Ultrasound
    • very little sensation is associated with treatment (dosage hard to monitor)
    • Pressure is exerted on the part to be treated ( aggravating any tenderness)
    • Only small areas can be treated at one time
  29. Indications for Ultrasound
    • subacute and chronic treatment of soft tissue dysfunction (sprain, strain, contusions)
    • Scar tissue
    • Joint Contracture
    • Chronic Inflammations
    • Increased extensibility of collagen
    • Reduction of muscle spasm
    • Pain modulation
    • Increased blood flow
    • Tisue regeneration
    • Bone healing
    • Repair of nonunion fractures
    • Plantar warts
  30. Contraindications of ultrasound
    • Areas of decreased temperature sensation and circulation
    • Vascular Insufficiency
    • Thrombophletitis
    • Over eyes
    • Infections
    • Over metal implants
    • Reproductive organs
  31. Precautions
    • acute inflammtion
    • epiphyseal plates
    • fractures
    • breast implants
    • keep tranducer moving
    • maintain even contact
    • remove air bubbles
  32. Application of Ultrasound
    • Intensity
    • Frequency
    • Sound Head Size
    • Durations
    • Duty Cycle
Card Set
Therapeutic Ultrasound
Exam 1