Ultra Sound Flashcards
What is sound?
Sound consists of waves that transmit energy by alternating compressing and rarefying material
“Ultra” means what for Usound?
- Usound can be greater then 20,000 Hz
How is sound transmitted?
Through a medium that travels through a material
What is the definition of frequency in sound waves?
The number of compression - rarefaction cycles per unit of time, expressed in cycles per second or Hz
At what frequency is therapeutic Usound used?
3 HHz million cycles per second
What determines which frequency is used with therapeutic ultrasound?
It depends on the depth of tissue needed to pernetrate
Continuous Usound
- Increases tissue temperature
Pulsed Usound
Non-thermal effects
Duty Cycle for Usound?
is the amount of on/off time
Continuous Duty Cycle?
100%
Mot common duty cycle for pulsed Usound?
1/5 Ratio, 20%/80%
In what measurement is the intensity of the Usound registered on the Usound unit?
W/cm^2
Cavitation
The formation, growth and pulsation of gas-filled bubbles caused by Usound
Stable Cavitation
- Bubbles oscillate in size throughout many cycles, but don’t burst
Unstable Cavitation
Bubbles grow over a number of cycles and suddenly implode
ERA
Effective Radiating Area
Contraindications of Usound
- Malignant Tumor
- Pregnancy
- CNS Tissue
- Joint Cement
- Plastic Components
- Pacemaker
- Thrombophlebitis
- Eyes
- Reproductive Organs
- Superficial Bone
What is the purpose of thermal treatment of Usound?
- Increase metabolic rate
- Decrease pain
- Decrease mm spasm
- Alternation of nerve conduction velocity
- Increase circulation
- Increase soft tissue extensibility
What should take place immediately after Usound?
- Exercise
- Stretching
- STM
- Use it or lose it
How long should Usound be done?
5-10 minutes, 2x the size of the ERA
If a pt reports pain with Usound what should you do?
Adjust parameters or stop treatment and check pt
What can cause pain with Usound?
- Intensity is too high or low
- Holding Usound head in one spot
- Not enough medium
- Not keeping the Usound head flat
Amount of Gel used?
Enough medium to eliminate air between area and sound head
Movement of Usound head?
Over lap by 1/2 of ERA, circles, switchback, figure 8
Rate of transducer movement?
4cm per second
Position of Usound head?
keep flat and in constant parallel contact with the skin
What is the most common size of transducer?
5cm head
How do you determine what size of transducer to use?
1/2 of the ERA
Watts
Total amount of energy used throughout the entire treatement
W/cm^2
Refers to the total amount of vibrational energy being delivered per unit area
What parameters does “dosage” incorporate?
Duty Cycle, Frequency, Intensity, Duration and sound head
Deep Heat
1 MHZ @ 1.0-2.5 W/cm^2
Pain Control
1.5 MHZ @ 2.0 W/cm^2
How is the treatment time for Usound determined?
Goal of treatment and ERA
What structures does Usound not effectively heat?
Fat
LOW ABSORPTION COEFFICIENTS
What structures does Usound effect?
- Tendons
- Ligaments
- Joint Capsules
- MM Tissue
- Fasia
ALL ARE HIGH ABSORBTION COEFFICIENTS
Low Intensity Pulse
- Dermal Ulcers
- Bone Growth
- Phono
- Acute Tendon and Ligament injuries
- Surgical Sutures
High Intensity Continuous
- Pain control
- Soft Tissue Shortening
- Carpal Tunnel
- Chronic Injuries
