Therapeutic Ultrasound Flashcards
What is therapeutic ultrasound?
Type of sound wave
Frequency is greater than 20,000 Hz (Cycle per second)
Exceeds the limits of normal human hearing
What is the physical effect of ultrasound?
Thermal & Non-thermal
What does the thermal effect of ultrasound do?
Increase tissue temp
What does the non- thermal effect of ultrasound do?
Acoustic streaming
Microstreaming
Cavitation
May alter cell membrane permeability
What type of ultrasound do you use to produce thermal effects?
Continuous
What type of ultrasound do you use to produce non thermal effects?
Pulsed
What are the thermal effects of ultrasound?
Acceleration of metabolic rate
Reduction or control of pain & muscle spasm
Alteration of nerve conduction velocity
Increased soft tissue extensibility
True or false: Ultrasound heats tissue with a high absorption coefficient more than tissues with low absorption coefficents
True
Is ultrasound ideal for heating muscles>
No b/c muscle has relatively low absorption coefficient & most muscle are larger than transducer
True or False: Tissues with higher absorption coefficients generally have higher collagen content
True
What factors affect the amount of temperature increase?
Tissue
Frequency
Intensity
Duration
What is one big thing that does not affect the amount of temperature increase?
Speed does not affect temperature change
What can happen if ultrasound intensity is too high? And what should you do?
Patient will most likely complain of deep ache because you are overheating the periosteum
You should reduce ultrasound intensity immediately
What can happen if ultrasound intensity is too low>
Patient will not feel any increase in temperature
What should tissue temperature be when using ultrasound?
40-45 *C