1. Therapeutic Ultrasound
Clinical Application
© 2005 – FA Davis

2. FDA Labeling Requirements
Output frequency
Effective Radiating Area (ERA)
Beam Nonuniformity Ratio (BNR)
Beam profile
Date of last service/calibration should also be posted on the unit
© 2005 – FA Davis

3. Treatment Area US heats a limited area
About the size of a catsup packet
Treatment area should be 2 to 3 times the size of the ERA
For larger areas, divide the treatment area into smaller zones
© 2005 – FA Davis

4. Direct Coupling Immersion Method Pad/Bladder Method
Coupling Methods
Direct Coupling Immersion Method Pad/Bladder Method
© 2005 – FA Davis

5. Coupling Methods Ultrasonic energy cannot pass through the air
A coupling medium is required
Medium should be water-based
Coupling method should confirm to the body area
The body area should be clean and relatively hair-free
© 2005 – FA Davis

6. Direct Coupling Gel or Creams Only use approved coupling agents
Apply liberally to area
Remove air bubbles by passing sound head over area (before power is increased)
© 2005 – FA Davis

7. Direct Coupling Move the sound head s-l-o-w-l-y
4 cm/sec
Moving the head faster decreases heating
If the patient describes discomfort, decrease the output intensity
© 2005 – FA Davis

8. Coupling Ability of Various Media
Substance Transmission
Saran Wrap 98
Lidex ge, fluocinonide (.05%) 97
Thera-Gesic 97
Mineral oil 97
US Transmission gel 96
US Transmission lotion 90
Chempad-L 68
Hydrocortisone powder (1%) 29
Hydrocortisone powder (10%) 7
Eucerin cream 0
Myoflex 0
White petrolatum gel 0
© 2005 – FA Davis

9. Immersion Technique Used to treat irregularly shaped areas
The limb is immersed in a tub of degassed water
If tap water is used, increase the output intensity by 0.5 w/cm2
Transducer is held appx. 1” from the body part
Avoid the formation of air bubbles
© 2005 – FA Davis

10. Pad (Bladder) Method A mass of conductive gel
Commercial pads
Self-made bladders
Conforms to the treatment area
Commercial pads help limit the size of the treatment area
© 2005 – FA Davis

11. Output Frequency Duration Duty Cycle Output Intensity
Output Parameters
Output Frequency Duration
Duty Cycle Output Intensity
© 2005 – FA Davis

12. Output Frequency Determines the treatment depth 1 MHz Output
Deep (5 to 7 cm) tissues
Rotator cuff, vastus intermedius, gastroc
3 MHz Output
Superficial (up to 3cm deep) tissues
Patellar tendon, MCL, brachialis
Remember that adipose tissue is transparent to ultrasound
© 2005 – FA Davis

13. Treatment Duration Depends on: Vigorous heating
Size of the treatment area
Output intensity
Therapeutic goals
Vigorous heating
1 MHz output
10 to 12 minuts
3 MHz output
3 to 4 minutes
Also see “Output Intensity”
© 2005 – FA Davis

14. Duty Cycle Determine the proportion of thermal and nonthermal effects
High duty cycle: Predominantly thermal effects
Low duty cycle: Predominantly nonthermal effects
Thermal effect used in subacute and chronic conditions
Nonthermal effects may be beneficial in acute stages
© 2005 – FA Davis

15. Output Intensity – 1 MHz At a 100% duty cycle 1.75 W/cm2 output
Approximately 4 min treatment is required to increase tissue temp 4°C
© 2005 – FA Davis

16. Output Intensity – 3 MHz At a 100% duty cycle 1.5 W/cm2 output
Approximately 10 min treatment is required to increase tissue temp 4°C
© 2005 – FA Davis

17. Ultrasound and Electrical Stimulation
“Combo Treatment”
© 2005 – FA Davis

18. US/Electrical Stimulation
Theoretically combines the benefit of the two treatments
Used to treat:
Trigger points
Muscle spasm
Output parameters:
Thermal ultrasound
Motor level electrical stimulation
© 2005 – FA Davis

19. Set-up and Application
© 2005 – FA Davis

20. Contraindications Acute injuries (100% duty cycle) Ischemic areas
Areas of impaired circulation including arterial disease
Over areas of deep vein thrombosis
Anesthetic areas
Over cancerous tumors
Over sites of active infection or sepsis
Over the spinal cord or large nerve plexus in high doses
Exposed metal that penetrates the skin (e.g., external fixation devices)
Areas around the eyes, heart, skull, or genitals
Over the thorax in the presence of an implanted pacemaker
Pregnancy when used over the pelvic or lumbar areas
Over a fracture site before healing is complete
Stress fracture sites or sites of osteoporosis
Over the pelvic or lumbar area in menstruating female patients
© 2005 – FA Davis

21. Precautions Symptoms may increase after the initial treatments.
Use caution when applying ultrasound around the spinal cord, especially after laminectomy.
The use of ultrasound over metal implants is not contraindicated
Keep the sound head moving
Use caution when applying ultrasound over epiphyseal plates of growing bone
© 2005 – FA Davis

22. Instrumentation
Duty cycle: Adjusts between continuous and pulsed ultrasound application
Frequency: Selects the depth of penetration
Gel warmer: Used to preheat the transmission gel, primarily for patient comfort
Intensity: Adjusts the output intensity.
The WATT METER displays the output in either total watts or watts per square centimeter.
Maximum head temperature: Prevents overheating in case the head is not properly coupled.
Pause: Interrupts the treatment but retains the remaining amount of treatment time
Power: Turns the unit ON or OFF
Start-Stop: Initiates or terminates the production of ultrasound from the transducer.
Timer: Sets the duration of the treatment.
Watt meter: Displays the output of ultrasound in total watts or watts per square centimeter.
© 2005 – FA Davis

23. Patient Preparation Establish that no contraindications are present
Determine the method and mode of ultrasound application to be used
Clean the area to be treated
Determine the type of coupling method to be used
Identify a treatment area that is 2 to 3 times the ERA
For direct coupling: spread the gel over the area to be treated
Explain the sensations to be expected during the treatment:
Mild to moderate warmth (but not pain or burning) for thermal treatments
No subcutaneous sensations during pulsed ultrasound
For thermal treatments pre-heating with a moist heat pack will decrease the treatment time required to reach vigorous heating levels
Advise the patient to report any adverse, unusual, or painful sensations during the treatment.
© 2005 – FA Davis

24. Initiation of the Treatment
Reduce the INTENSITY to zero before turning on the POWER.
Select the appropriate mode for the output (CONTINUOUS or PULSED)
Set the WATT METER to displays the appropriate output for the type of treatment
Set the TIMER to the appropriate treatment duration
Begin slowly moving the sound head over the medium
Press the START button to begin the treatment session
Units having low BNR may be moved at a slower rate than those with a higher BNR
Slowly increase the INTENSITY
Keep the sound head moving
Move the head at a moderate pace (4 cm per second or slower)
Use firm, yet not strong, overlapping strokes
If pain is experienced:
Move the sound head at a faster rate
Use a lower duty cycle
Use a lower the intensity
If the gel begins to wear away or if the sound head begins sticking on the skin, depress the PAUSE button and apply more gel
© 2005 – FA Davis

25. Phonophoresis Application
Preheating the area to increase the absorption of the medication
Use only approved ultrasound transmission media.
The direct coupling method is recommended
Efficacy of phonophoresis using the bladder method has not been established
Ensure that the skin is well moistened; avoid areas of dry skin
Position the extremity to encourage circulation.
Use a continuous output to maximize the effect of phonophoresis
Unless the thermal effects of ultrasound are contraindicated
Follow the procedures described in “Initiation of the Treatment”
After treatment, cover the remaining medication with an occlusive dressing.
© 2005 – FA Davis

26. Termination of the Treatment
If the treatment is being terminated prematurely:
Reduce the intensity before removing the transducer
Clean the remaining gel from the patient’s skin
To ensure continuity of treatment sessions:
Record the treatment parameters
Output frequency
Intensity
Duration
Duty cycle
Running count of ultrasound treatments given for this condition
Immediately initiate any post-treatment stretching
© 2005 – FA Davis

27. Maintenance Daily Maintenance
Clean ultrasound head and transducer face as recommended by the manufacturer
Monthly Maintenance
Check all electrical cords for frays or kinks
Check the sound head cable for frays or kinks
Clean the transmitter face as recommended by the manufacturer.
Federal regulations require that therapeutic ultrasound units be recalibrated annually by an authorized service technician
© 2005 – FA Davis