Ultrasound Flashcards
Therapeutic ultrasound ranges from (MHz)
.75 - 3 MHz (1 - 3MHz is most common)
Effects of Ultrasound can include: (7)
Increased rate of tissue repair Wound healing Increased blood flow Increased tissue extensibility Breakdown of calcium deposits Reduction of pain and muscle spasms Changes in cell permeability
Properties of Sinusoidal waveform (4)
Wavelength
Frequency
Amplitude
Velocity
Define MHz
Cycles per second
1MHz output targets tissues up to how many cm deep?
5cm
3MHz output targets tissues up to how many cm deep?
2cm
Define Effective Radiating Area
The area of the sound head that produces ultrasonic waves measured in square centimeters
Define Intensity
Describes the amount of power generated by a unit-strength of the sound waves
Define Spatial Average Intensity
Measured in watts per square cm. SAI describes the amount of energy (power) per unit area of the sound heads ERA.
Standard tx range from 0.5 to 3 w/cm2
Formula for Duty Cycle
DC = pulse length/(pulse length + pulse interval) x 100
Ultrasound output depends on what 4 factors?
Mode of application (pulsed or continuous)
Intensity and frequency of output
Vascularity of tissues
Speed of movement of the sound head
Thermal effects of Ultrasound (7)
Increased sensory nerve conduction velocity
“” motor nerve conduction velocity
“” extensibility of collagen-rich structures
“” blood flow
“” macrophage activity
Reduction of muscle spasms
Enhanced adhesion of leukocytes to damaged endothelial cells
Mild thermal effects include (3)
an increase of tissue by 1 degree C
Used for mild inflammation
Acceleration of metabolicrate
Moderate thermal effects include (4)
Increase of tissue temp by 2-3 degrees C Used for: decreasing muscle spasm and pain increasing blood flow reducing chronic inflammation
Vigorous thermal effects include (4)
Increase of tissue temp by 3-5 degrees C Used for: tissue elongation scar tissue reduction inhibition of sympathetic activity
Ultrasound Non thermal effects
Increased cell permeability "" vascular permeablity "" blood flow "" fibroblastic activity Stimulation of phagocytosis Production of healthy granulation Synthesis of protein Reduction of edema Synthesis of collagen Diffusion of ions Tissue regeneration
Ultrasound Injury Response Process (3)
Increased histamine release
“” intracellular calcium
“” protein synthesis
Phonophoresis delivers meds via…
Open pathways (follicles, pores, sweat glands) Delivers up to 6cm in depth
Skin factors for Phonophoresis (5)
Hydration Age Composition Vascularity Thickness
Duration and Frequency of Treatment
3 - 12 minutes
10 - 14 treatments once/day then evaluate for efficacy of protocol
Ultrasound Indications (6)
Joint contractures Muscle spasm Scar tissue Trigger areas Acute inflammatory conditions (pulsed) Chronic inflammatory conditions (cont. and pulsed)
Contraindications are (12)
Acute conditions (cont.) Ischemic areas Tendency to hemorrhage Areas around eyes, heart, skull, genitals Pregnancy (lumbar/pelvic region) Over spinal cord Anesthetic areas Fracture site before complete healing Stress fracture sites Sites of active infection Areas of impaired circulation Over the pelvic or lumbar area in menstruating female patients
