1. Microwave Diathermy ELECTROTHERAPY
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

2. OBJECTIVES OF THE LECTURE
1. Define microwave current
2. Review the physics of the current
3. Effects of application
4. Indications
5. Contra-indications
6. Procedure of application
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

3. Microwave Diathermy
Microwaves are a form of electromagnetic radiation, lying between the shortwaves and infrared waves. Their frequencies ranges between 300 and MHz with wavelengths of 10mm to 1 meter.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

4. Microwave Diathermy
Microwave diathermy is a deep heating modality, similar to short wave diathermy but differs in its physics and mechanical properties. Physics: The clinical microthermy frequency is limited to Mc range (10-12 cm wavelength), which is shorter than short wave diathermy.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

5. Magnetron
The high frequencies of microthermy are obtained from a unique device called the magnetron, which is perforated with tiny holes, through which the electrons flow into the treatment heads.
The special design of the treatment heads shapes and focuses the field directly at the target area.
The whole device is used to direct the waves onto the tissues.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

6. Transducer Magnetron Power supply Antenna Reflector Timing circuit
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

7. Microwave emission by:
This device is sometimes termed *the emitter, *the director or *the applicator.
In this kind of treatment, the patient does not form a part of the circuit, so no tuning is necessary as in short wave application.
Microwave emission by:
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

8. Microwave Radiation
The heat produced by microthermal radiation is known to be more concentrated than that produced by short wave diathermy.
Although penetration is theoretically increased with higher frequencies, absorption still depends on the target density and the intervening tissues.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

9. Microwave Penetration
According to the differences in absorbability of tissues, the clinical effect of microwave radiation depends on the type of tissue involved.
Tissues with low water content are penetrated to a greater depth.
Tissues with a high water content are penetrated to a lesser depth.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

10. Physiological Effects:
Absorption of the waves results in production of heat in the tissues, but differs from other heat treatment methods in the distribution of heat. Electromagnetic energy is transformed into heat energy. Microwave is not suitable for deeply placed structures.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

11. Penetration of the Microwaves
The effective depth of microwave penetration is about 3 cm, so the depth of heating is intermediate between that of infrared radiation and short wave diathermy.
As the microwaves are strongly absorbed by water, tissues with high fluid content are heated most, while less heat is produced for tissues with low fluid content as fat or bones.
Moreover, there is an appreciable heating of tissues having good blood supply such as muscles.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

12. Reflection
The proportion of waves reaching the deeper layers of the tissues depends also on the amount of energy reflected at the air/skin surface.
As much as 50% of the energy can be reflected.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

13. Indications:
The clinical indications for microthermy are, more or less, similar to those for short wave diathermy.
Microthermy may be preferable to short wave when more concentrated or localize heating is needed.
Traumatic and inflammatory lesions, in which increase of blood supply and relief of pain and muscle spasm are required.
Lesions in the superficial regions and those of high fluid content.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

14. INDICATIONS (2)
Traumatic and rheumatic conditions affecting soft tissues and small superficial joints.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

15. INDICATIONS (3) Superficial infections such as septic fingers,
carbuncles and
other superficial abscesses.
It heals by increased circulation with increased white blood cells and antibodies
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

16. Indications Pain relief ( muscular origin)
Healing of the skin ( by direct application on the wound or by reflex vasodilatation to a proximal level of the wound)
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

17. Contraindications and precautions:
Burns: As water is heated rapidly by microwaves, burning of wet skin may occur.
Eyes: Irradiation to the eyes may develop opacities.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

18. Contraindications
Circulatory defects: Such as hemorrhage, thrombosis, phlebitis and other vascular lesions.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

19. Contraindications
Malignancy: Microwave diathermy should not be applied to regions of malignant
growth or tubercular infections (tuberculosis).
Cardiac pacemakers.
Genital area ( sterility).
Pregnancy (miscarriage , hemorrhage)
Obesity, unreliable patients, metallic implants, hypersensitivity to heat, impaired sensation
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

20. Treatment procedures:
1. Selection of the treatment head (Director):
Generally, two designs of directors are found:
Circular: In which heat is denser at the periphery more than at the center.
Two sizes of circular directors are available:
Small: for small areas.
Large: for large areas.
- Rectangular: for elongated areas.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

21. Selection of the treatment head
The director selection depends on the shape and the anatomical configuration of the treated area.
The actual distance from the director to the skin will determine the extent of the treatment zone.
It can be detected by passing an ordinary fluorescent lamp between the treatment head and the patient’s skin.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

22. 2. Preparation of the patient:
The target area should be bare skin.
Clean the skin thoroughly to avoid refraction or burn if the skin is wet.
Choose the comfortable position for the patien on a wooden stool.
No towel is needed.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

23. 3. Monitoring the treatment:
The target distance will determine the power levels, as the closer the director to the skin, the lower the power levels and vice-versa.
A warm-up period must be allowed to permit the magnetron to develop enough efficiency (+-4 minutes).
The desired sensation of the patient is gentle warmth.
Reports of hot spots should be attended immediately either by reducing the power or increasing the distance.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

24. 4. Duration of treatment:
Treatment by microthermy requires between 10 and 20 minutes.
Generally, smaller target areas need less time, while larger ones need more.
Treatment may be applied daily or every other day.
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

25. Advantages Operation of the machine is simple
Comfortable for the patient
Localised heat to small surfaces
No overheating if precautions are followed
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

26. Disadvantages Not for deep structures
Heats only one aspect of the joint
No accurate measurement of the energy given and the heat received by the patient
Risk of burn
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux

27. THANK YOU
Electrotherapy Prof. Khaled Mamdouh, Ms. I. Devreux