Introduction, properties, Production, Therapeutic effects, Indications, Contraindications

1. 6/17/2022
P/B:-Dr.NIYATI PATEL 1

2.  Long wave
- longest wavelength 300 – 30 m
- most penetrating
- no longer utilized due to high potential of
causing burns and interference with radio
transmissions
6/17/2022
P/B:-Dr.NIYATI PATEL 2

3.  Microwave diathermy (MWD), is a form of
electromagnetic radiations lying between
shortwave and infrared waves.
 Microwave diathermy does not penetrate as deep
as shortwave diathermy.
 The energy is first absorbed at the surface of the
body (skin) and a part of it penetrate and
absorbed in deep tissues.
 Generates Strong Electrical Field and Relatively
Little Magnetic Field
6/17/2022
P/B:-Dr.NIYATI PATEL 3

4.  Microwave has a much higher frequency and a
shorter wavelength than shortwave diathermy.
 The general frequency of microwave is between 300
MHz to 300 GHz with wave length of 10 mm to 1
meter.
 The therapeutic microwave generators used
frequency of 2450MHz with wave length of 122.5mm.
 Physiotherapeutic microwaves at 327mm (915 MHz)
and 690mm (433.9MHz) may be also available to give
minimal heating of subcutaneous tissues and produce
more heating of underlying tissues.
6/17/2022
P/B:-Dr.NIYATI PATEL 4

5. The generator used to produce microwaves has
three main components:
1- A multi-cavity magnetron valve
2- A coaxial cable
3- A director.
Mechanism of MW production
 The magnetron produces a high frequency
alternating current which is carried by coaxial
cable to the transducer (director).
 The coaxial cable transmit the energy to the
director where a radiating system comprising
an antenna within a reflector that is used to
direct the microwave to the patient.
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6.  The alternating current in the antenna produces
an electromagnetic field that is directed toward
the tissue by a curved reflecting director
surrounding the antenna.
 The presence of a director and the short
wavelength of microwave radiation allow this type
of diathermy to be focused and applied to small,
defined areas.
 Therefore these devices can be useful during
rehabilitation when only small areas of tissue are
involved.
6/17/2022
P/B:-Dr.NIYATI PATEL 6

7. 6/17/2022
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8.  Circular directors
- The heating pattern is
more intense around the
outer portion than the
centre.
- There are small and large
 Rectangular directors
The heating pattern tends to
be more concentrated in the
center of the treated area.
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9.  MWD tend to be reflected and scattered at different
interfaces as air-skin, skin-fat, and the fat-muscle
which limit its penetration into the tissues.
 Because of the spreading of MW, the superficial
tissues tend to be heated more than deeper tissues.
 Depth of penetration depends on the frequency of the
wave and the medium. The effective penetration of
2450MHz is approximately 3 cm.
6/17/2022
P/B:-Dr.NIYATI PATEL 9

10.  Pain: MWD is useful in the treatment of
traumatic and rheumatic conditions
affecting superficial muscles, ligaments and
small superficial joints.
 Muscle spasm: which may be reduced
directly by MWD or may be reduced by
relieving of pain.
 Inflammation: MWD reduces inflammation
by increase blood supply that will increase
venous return from the inflamed area and
aids the reabsorption of edema exudates.
6/17/2022
P/B:-Dr.NIYATI PATEL 10

11.  Delayed healing: MWD promotes healing of
open skin by increase cutaneous circulation.
 Infection: MWD can control the chronic
infection by increasing the circulation.
 Fibrosis: The heating effect of MWD
increase the extensibility of fibrous tissues
such as tendons, joint capsules and scars.
6/17/2022
P/B:-Dr.NIYATI PATEL 11

12. - The clinical indications for MWD are, more or less,
similar to those for SWD.
- MWD may be preferable to SWD when more
concentrated or localize heating is needed.
 Musculoskeletal disorders:
- Sprain - Muscle & tendon tear
- Strain - Degenerative joint disease
- Joint stiffness in superficial joints
- Capsular lesions.
 Superficial inflammatory or infective conditions :
- Tenosynovitis - Bursitis
- Synovitis - Abscess
- Infected surgical incisions
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P/B:-Dr.NIYATI PATEL 12

13.  Over malignant tissues. Increase metabolism due to increase the
temperature would accelerate the rate of growth & metastasis of
malignancy
 Over ischemic tissues. Inability of the circulation to disperse the heat
could result in temperature elevation to that level which produce burn and
increase oxygen requirement so its produce gangrene
 Over wet dressings and adhesive tapes. More absorbed and burn
and scald could result.
 Metal implants. More concentration around implant area it leads to
burn
 Pacemaker. Interfere in pacemaker settings and inhibit the function of
some pacemaker
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14.  Over growing bone. Limit the bone growth
 Male gonads. repeated irradiation can cause infertility.
Gonads should be shielded by fine wire mesh
 Hemorrhage. Increase the circulation so increase the
hemorrhage
 Impaired thermal sensation. the pt reports the degree of
heat felt if any disturbance in or loss of thermal sensation could result in
high intensities being applied it leads to tissue distruction
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P/B:-Dr.NIYATI PATEL 14

15.  Recent radiotherapy. Up to 3 months of radiotherapy skin sensation
and circulation are diminished
 Hypersensitivity to heat. Disperse the heat
 Acute infection or inflammation. Exacerbated by heat application
 Venous thrombosis or phlebitis. Heat applied to the affected area
may result in embolus formation
 Pregnancy. heat applied to pelvis or hip in pregnancy may cause
hemorrhage or miscarriage.
 Acute dermatological conditions. Active phase of multiplication of
bacteria/infectious cell.
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P/B:-Dr.NIYATI PATEL 15

16.  The same as SWD, but it is recommended to
avoid the presence of metal within the
treatment field (4 feet) because of scattering
and reflection of MWD
 Due to scattering and reflection of MWD to the
surrounding environment, it has been
associated with high incidence of miscarriages
among female therapists who regularly operate
these units than SWD.
 The eyes: MWD may cause cataract.
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P/B:-Dr.NIYATI PATEL 16

17.  Obesity: MWD with 2450MHz, there is
danger of producing an excessive heat in
the subcutaneous fat layer
 Burn: There is an increasing of risk of
excessive heating and burning with the
using of MWD due to:
1.Shallow depth of penetration
2.Reflection at tissue interfaces
3.Potential standing waves
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P/B:-Dr.NIYATI PATEL 17

18.  Duration of treatment: 20 minutes is the
optimum.
 Intensity: the patient should feel mild and
comfortable warmth.
 Frequency: daily or on alternating day.
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19. 6/17/2022
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20. 6/17/2022
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21. 1. Properties of MWD
2. Frequency and wavelength
3. Mw production & device
4. Directors used in mw applications
5. Biophysics of MWD (P.A.R)
6. Therapeutic effects
7. Indications of MWD
8. Contraindications
9. Precautions and dangers
10. Dosage
6/17/2022
P/B:-Dr.NIYATI PATEL 21

22. 6/17/2022
P/B:-Dr.NIYATI PATEL 22