Short wave diathermy
Definition
(Short wave diathermy): It is a means of producing
therapeutic heat in the tissue by the use of radio waves of high frequency
current.
Physiological
effects of SWD:
1)
Effects
of electric field: The free ions in the tissue fluid
move backwards along the lines of force of the field as the change alternates
on the condenser plates. Because the charge alternates at a high frequency the
movement is minimal and may be termed a vibration of the ions. As a result of
the vibration friction occurs between ions and the result of the friction is
the production of heat in the tissue.
2)
Effects
of electromagnetic field: The electromagnetic
field produces eddy current which are circular currents at right angle to the
lines of force. They tend to be more concentrated near the surface of the
conductor that is in the superficial tissues. The friction of the tissue
particles produces by these current and by the associated electromagnetic field
result in the production of heat.
3)
Heat
production: The only proven physical effects of
short wave diathermy are the production of heat as a result of the effects of
the electrostatic and or electromagnetic field setup in the tissue. Heat will
be produced in all tissues affected by the field, but will be concentrated in
the tissue of low resistance. Mild heat produces reflex reduction of muscle
tone. It is suggested that increased muscle blood flow plays same part in this
mechanism, along with removal of the trigger irritation.
When
the temperature at nerve or in subcutaneous tissues with a high proportion of
cutaneous nerve fibers is elevated to above 45 dgr then neural stimulation
resulting in various reactions and blood pressure and vascular response are seen.
Mild heating causes an analgesic effect in the underlying tissues.
Therapeutic
effects of SWD:
1)
Relief
of pain: The relief of pain by SDW is useful in
the treatment of traumatic and rheumatic conditions affecting muscles,
ligaments, bones and joints. Pain also relived by breaking the vicious cycle of
pain and muscle spasm.
2)
Muscle
spasm: Muscle spasm may be reduced directly by SDW acting
on the nerve fibers. Muscle spasm also is reduced by relieving the pain which
contribute to it.
3)
Reduced
inflammation: Resolution of chronic inflammation may
be accelerated by treatment with SWD as a result of the increase in blood
supply. This increases venous return from the area and aids the resorption of
the edema exudates.
4)
Acceleration
of healing: SWD causes vasodilatation.
Vasodilatation increases circulation. Increased circulation allows more
nutrition. Increased supply of nutrition accelerates healing the damaged areas.
5)
Control
of infection: SWD may assist in the control of
chronic infection by increasing the circulation. This will increase the number
of white blood cells and antibodies brought to the area to fight the infective
organism.
6)
Removal
of fibrosis: SWD has been found to increase the
extensibility of fibrous tissues, such as tendons joint capsules and scars 5 to
10 times. The effects are produced by temperature increase within the
therapeutic range.
Indication
of SWD: Short wave diathermy may be indicated
for the treatment of both deep and superficial structures. It could be
indicated for the treatment of:
[A]
Disorders of musculo-skeletal system:
1)
Joint contractures.
2)
Joint stiffness.
3)
Resorption of haematoma.
4)
Sprains.
5)
Strains.
6)
Muscle and tendon tears.
7)
Capsule lesions.
8)
Degenerative joint disease
9)
Chronic rheumatoid arthritis.
[B]
Chronic inflammatory or infective conditions:
1)
Tenosynovitis.
2)
Bursitis.
3)
Synovitis.
4)
Infected surgical incision.
5)
Carbuncles.
6)
Abscesses.
7)
Sinusitis.
8)
Dysmenorrhoea.
Contraindication
of SWD:
1)
Moderate
and excessive edema: Non-inflammatory edema is
particularly likely to be aggravated by the administration of any form of heat.
2)
Over
wet dressing and adhesive tape: SWD will be more
readily absorbed and a burn or scald could result.
3)
Topical
creams and oils: All topical application must be removed
before giving SWD; otherwise the creams and oils will cause a burn.
4)
Metalic
implant: Any metal within the field of the SWD
application will concentrate the field and result in production of temperatures
in the burn to the surrounding tissue.
5)
Superficial
metal: There should be no metal in the area of the SWD
application. Metal retains the heat and will cause a burn to the underlying
tissue.
6)
Cardiac
pacemakers: It is not advisable to apply the SWD in
the region of the thorax or the pacemaker control unit as it may interfere with
the function of the pacemaker.
7)
Hemorrhagic
area: The increase in circulation will increase the degree
of hemorrhage.
8)
Tuberculosis:
SWD will aggravate the condition.
9)
Impaired sensation.
10)
Unreliable patient.
11)
Deep x-ray therapy.
12)
Hypersensitivity to heat.
13)
Inflammation:
Any acute inflammation with an underlying danger of infection or with
thrombosis may exaggerate.
14)
Analgesic
and narcotic drugs: If patient have had strong
analgesic or narcotic drugs the thermal sensation may be diminished. So SWD
must not be given.
15)
Pregnancy:
SWD to the pelvis may induce hemorrhage or miscarriage.
16)
Dermatological condition.
17)
Sever cardiac condition.
18)
Blood pressure abnormalities.
Describe
how heat is produced with in tissue with short wave diathermy:
Heat
production: The only proven physical effects of
short wave diathermy are the production of heat as a result of the effects of
the electrostatic and or electromagnetic field setup in the tissue. Heat will
be produced in all tissues affected by the field, but will be concentrated in
the tissue of low resistance. Mild heat produces reflex reduction of muscle
tone. It is suggested that increased muscle blood flow plays same part in this
mechanism, along with removal of the trigger irritation. When the temperature
at nerve or in subcutaneous tissues with a high proportion of cutaneous nerve
fibers is elevated to above 45 dgr then neural stimulation resulting in various
reactions and blood pressure and vascular response are seen. Mild heating
causes an analgesic effect in the underlying tissues.
Factors
influences field distribution in short wave Diathermy:
Spacing:
Spacing allows the lines of force in the electrostatic field to diverge before
entering the tissues. This prevents concentration of heat in the superficial tissues
and ensures more even heating through the part. Effects of spacing
Normal spacing- Even
field distribution.
Increased spacing- Deep
field concentration.
Decreased spacing-
Superficial field concentration.
Metal:
Metal causes the lines of force to concentrate in the metal; this concentration
of the lines of force will result in burning of adjacent tissues.
Air
in cavities: These causes the lines of force to
deviate to avoid the air. As a result only the sides of an air filled cavity
will be heated.
Electrode
size:
·
Smaller then the diameter of the limb-
the lines of force will be concentrated superficially, producing greater heat
in those tissues.
·
Markedly larger than the diameter of the
limb: Some of the lines of force will travel through the air and effect will
lost.
·
Slightly larger than the diameter of the
limb: Ensuring even distribution of the lines of force throughout the tissue.
Dangers
of short wave diathermy: There are two dangers
may occur:
·
Burns.
·
Shock.
Advantages
of pulse SWD:
·
Pulse short wave can often be used in
conditions where non-pulsed short wave is contraindicated.
·
In particular pulsed short wave is
effective in the treatment of post traumatic and infective conditions.
Hi,
উত্তরমুছুনNice article, thanks for sharing, keep up the good work...http://howtorelief.com/short-wave-diathermy/
Very informative post, if there is any side effects by this SHORT WAVE DIATHERMY. The Refurbished valleylab force FX diathermy treatment is whether applicable for the muslce and joint pains???
উত্তরমুছুন