Advantages of Microwave diathermy | Disadvantages of Microwave diathermy
This page covers advantages and disadvantages of Microwave diathermy and its basics. It mentions benefits or advantages of Microwave diathermy and drawbacks or disadvantages of Microwave diathermy.
What is Microwave diathermy?
The diathermy is greek word meaning "through heating" in which high frequency EM current is applied to generate deep heating within body tissue to induce physiological effects for therapeutic purpose. It helps to relieve pain, to heal infections faster and helps to get relaxation. The diathermy which uses microwave frequency ranging between 300 to 3000 MHz with wavelengths from 1 meters to 10 mm is known as microwave diathermy.
Following typical microwave frequencies with their wavelengths are commonly used in microwave diathermy devices.
• 2450 MHz frequency with 12.33 cm wavelength
• 915 MHz frequency with 32.7 cm wavelength
• 433.9 MHz frequency with 69 cm wavelength
The figure depicts microwave diathermy generator with its internal components. As shown it consists of power supply, timing circuit, magnetron and transducer. The whole device is used to direct the waves onto the tissues. It uses antenna with head design such that it focuses the field directly at the target area. The high frequency waves are obtained from magnetron which is perforated with tiny holes through which electrons flow into the treatment heads.
The waves pass through intervening space and are absorbed to heat up the tissues at the desired depth to be treated. The effective depth of microwave penetration is about 4.5 cm which is intermediate between infrared (~ 2 cm) and short wave diathermy (>5cm).
Following are the treatment parameters of microwave diathermy.
• Spacing of applicators : 2-6 cm for small treatment area, 10-15 cm for large treatment area
• Time of treatment : 20 to 30 minutes
• Frequency of treatment : Daily or alternate days based on response of treatment, patients condition and availability.
Benefits or advantages of Microwave diathermy
Following are the benefits or advantages of Microwave diathermy:
➨The microwave diathermy technique and its machine operation is very simple. It does not require pads, electrodes, capacitor pads or inductive coils as in short wave diathermy.
➨It produces much more localized and concentrated heating effect than short wave diathermy.
➨It provides more shallow tissue heating effect depending on type of tissue involved. It is strongly absorbed by tissues with high fluid content such as muscle or blood and hence they are heated most with superficial depth of 0.7 cm. It is penetrated to greater depth by tissues with low fluid content such as fat or bones.
➨The patient does not form part of circuit in microwave diathermy and hence no tuning is necessary as in short wave diathermy.
➨It is very comfortable treatment method for the patients.
➨No overheating if precautions are followed.
➨Low frequency microwaves causes selective heating in muscles.
Drawbacks or disadvantages of Microwave diathermy
Following are the drawbacks or disadvantages of Microwave diathermy:
➨No metal should be within 4 feet of microwave diathermy device, since it will interfere with the signal.
➨Various factors affect heat absorption e.g. water content, frequency, distance, laws of reflection, refraction, absorption and inverse square.
➨It is not suitable for deep structures.
➨Only one aspect of the body can be treated at a time.
➨There is risk of skin burns if treatment procedures and safety guidelines not followed properly.
➨Patients should not look at the applicator machine during treatment. Failing so will result into burns. It is recommended to use microwave goggles by the patient.