Therapeutic Ultrasound

• 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

• The number of wave cycles complete per second
• Increased frquency Increased focus of beam

.75-3MHz

• 1MHz= 2-5cm of penetration
• 3MHz= 1-2cm of penetration

• 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

• 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

• EFFECTIVE RADIATING AREA
• 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

• Deep Heat
• 2-5cm
• Helpful in Pt with high percent of body fat

• superficial heat
• 1-2cm
• absorbs energy 3 times faster tah 1MHz

• 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

• The sound intensity (heat) remains constand throughout the treatment
• 100%

• The inensity if periodically interruped
• no energy being produced during the off period
• Low % used during nontheramal or mechanial ultrasound

The Percentage of time that ultrasound is being generated (pulse duration) over one pulse period.

• Degree change
• A measure of the rate at which energy is being delivered per unit area

• 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

• 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

Collagen can be heated without heating the superficail heat

• Micomassage
• Alters Membrain Permeability
• Arteriolar vasoconstriction or dilation
• Cavitation
• Nonthermal effects of ultrasound maybe more important than thermal effects

• microscopic movement or oscillation of body fluids and tissues as a result of exposure to ultrasound
• "cellular Massage"
• Don't Feel this

• Acoustic microstreamin is the mechanism that induces changes in diffusion rates and membrane permeability
• affects swelling
• Keeps fluid in Vessels

Nontheram effect of arteriolar vasoconstriction or asodilation is not clear

Formation and collapse of gas or vapor filled cavities in liquids

• continuous ultrasound can increase local blood flow for up to 45 mins after treatment
• these findings are not universally accepted

• ultrasound application accelerates the inflammatory phase of tissue healing
• macrophage activity
• increases the adhesion of leukocytes to the damaged endothelial cells

• 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

• elevates pain threshold (changes cell membrane permeability to sodium ions)
• changes nerve conduction velocity
• Counterirritand effect

• capable of producing significant temperature changes deep within the tissue
• localized treatment
• application times are short

• 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

• 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

• Areas of decreased temperature sensation and circulation
• Vascular Insufficiency
• Thrombophletitis
• Over eyes
• Infections
• Over metal implants
• EPIPHYSEAL AREAS IN YOUNG CHILDREN
• Reproductive organs

• acute inflammtion
• epiphyseal plates
• fractures
• breast implants
• keep tranducer moving
• maintain even contact
• remove air bubbles

• Intensity
• Frequency
• Sound Head Size
• Durations
• Duty Cycle