Shortwave Diathermy

Clinical Application

Treatment Dosages

Pulse

Dose Sensation Width Rate (pps)

NT No warmth 65 µsec 100 – 200

1 Mild warmth 100 µsec 800

2 Moderate 200 µsec 800

3 Vigorous 400 µsec 800

Pulsed SWD Setup

Parameter SettingOutput mode: Pulsed

Bursts per sec: 800

Burst duration: 400 sec

Interburst 850 secinterval

Output intensity 150 W RMS

48 W/burstRMS

RMS = Root Mean Squared

Set-up and Application

Treatment Duration

Nonthermal, Mild, and Moderate Heating

• Duration – 20 to 30 minutes

• Repeated as needed

• Two weeks

Vigorous Heating

• Duration – 15 minutes

• Applied every other day

Precautions• Remove contact lenses when applying SWD around the head, face, or eyes.• The skin exposed to the treatment should be covered by at least 0.5 inch of toweling• Do not allow perspiration to collect in the treatment field.• Thick adipose tissue in the treatment area can result in overheating the skin.• It is difficult to heat only localized areas. Water pathways within the tissues dissipate

heat formed in the treated area.• Never allow the skin to come into direct contact with the heating unit or cables. • If the cable method is used, do not allow them to touch each other. • If electrode pads are used, space them at least the distance of their diameter apart.• A deep, aching sensation may be a symptom of overheating the tissues.• Overheating of the patient’s tissues may cause tissue damage without any immediate

signs. • The SWD energy scatters 2 to 3 feet from the source

– A distance of 3 feet from the source of the energy should be maintained to ensure the operator’s safety.

Instrumentation

• Master Power Switch: Turns the unit on.

• Output Intensity (Power): Adjusts the amount of energy delivered to the patient.

• Patient Interrupt Switch (Safety Switch): A pushbutton switch held by the patient that allows immediate termination of the treatment.

• Pause: Interrupts the treatment to allow repositioning of the patient, etc.

Instrumentation (Cont.)

• Pulse Rate (Pulse Frequency): Sets the number of pulses per second (PPS) for the output.

• Start/Stop: Initiates or terminates the treatment. • Treatment Timer: Sets the treatment duration. • Tuning: Adjusts the output resonance to match

the patient’s tissues.– Some units will shut off if an out of tune state is

detected– Most contemporary units are self-tuning

Patient Preparation • Ensure that the patient is free of

all contraindications to the use of shortwave diathermy.

• Remove all jewelry, clothing, coins, and other metallic items from the patient.

• For personal safety, the clinician should remove any rings, watches, bracelets, etc.

• There must be no metal within the immediate treatment area

• Keep the patient out of reach of any metal objects that can serve as a ground (e.g., outlets, pipes).

• Clean and dry the body part. Water, skin oils, etc. can increase superficial heat production.

Patient Preparation (Cont.)

• Position the patient in the most appropriate manner for the body area being treated.

• To encourage venous return, elevate the extremity being treated.

• To prevent burns cover the area to be treated with a dry terry cloth towel:– This provides spacing between the source of the shortwave

diathermy – Absorbs perspiration– A portion of the treatment area must remain visible to check for

burns during the treatment..• Explain to the patient that mild warmth should be felt. • Instruct the patient to inform you if any unusual

sensations are experienced.

Patient/Generator Tuning

If the unit must be manually tuned:• Position the electrodes over the patient.• Increase the output intensity to appx. 40% of the max.• Adjust the TUNING control until the output meter

reaches its peak…• … then decrease the TUNING to the patient’s comfort.• A unit is tuned when less than half of the maximum

output is used. – Some units will automatically shut off if more than 50 percent of

the maximum output is used. If this occurs, the unit must be tuned again.

Initiation of the Treatment

Drum Method• Turn the unit on; allow it to warm up if necessary.• Some units must be tuned to allow for maximal energy

transfer. • If indicated by the manufacturer’s instructions, place a

folded towel between the body part and the drum.• Position the drum approximately 0.5 to 1 in. above the

toweling. • The surface of the drum must be parallel to the skin

surface being treated, otherwise the skin closest to the drum will overheat (the Cosine Law)

Initiation of the Treatment (Cont.)

• Instruct the patient not to move until the unit is shut off.• Set the TIMER to the desired treatment duration.• Increase the intensity until the patient feels mild warmth.• If the drum must be moved or if it becomes necessary to

dry the area, return the intensity to zero before making any adjustments.

• Do not leave the patient left unattended • Regularly check the skin for signs of burns and inquire

about unusual sensations.– Adjust the INTENSITY, PULSE RATE, and/or electrode

placement as necessary.

Termination of the Treatment

• After the treatment, return the intensity to “zero” and shut off the unit.

• Inspect the skin for signs of burns or other abnormal treatment outcomes.

• Record the treatment parameters in the patient’s file.

Maintenance

Daily Maintenance• Clean the face of the drum or cables using

a manufacturer-approved cleanser.

Regular Maintenance• Inspect electrical cords for kinks and frays.Annually• The unit must be serviced and calibrated

by a qualified service technician.