microwave diathermy

components,indications,contraindications

1. MICROWAVE DIATHERMY DR.PRASHANTH KUMAR SVS MEDICAL COLLEGE

2. Microwave diathermy (MWD), is a form of electromagnetic radiations lying between shortwave and infrared waves. Where energy is first absorbed at the surface of the body (skin) and a part of it penetrate and absorbed in deep tissues. Microwave diathermy does not penetrate as deep as shortwave diathermy. INTRODUCTION

3. Microwave has a much higher frequency and a shorter wavelength than shortwave diathermy . Generates Strong Electrical Field and Relatively Little Magnetic Field The general frequency of microwave is between 300 MHz to 300 GHz with wave length of 10mm to 1 meter . INTRODUCTION

4. The therapeutic microwave generators used frequency of 2450MHz with wave length of 122.5mm. Microwave radiation is radiated as a beam from an antenna and absorbed by water-rich tissues 7000 times more effectively than shortwave radio frequency energy. INTRODUCTION

5. A microwave beam can be narrowed to allow small areas to be treated accurately, is highly directional , and can be aligned rapidly. Microwave energy is generated by an electronic device known as a MAGNETRON. The applicators consist of an antenna element backed by a reflector and endorsed within a plastic case , one face of which is transparent to microwave energy. INTRODUCTION

6. PANNEL DIAGRAM OF MWD

7. MWD Applicators (Electrodes) Circular Shaped Applicators 4” or 6” Maximum Temperature At Periphery 2. Rectangular Shaped Applicators 4.5 x 5” or 5 x 21” Maximum Temperature At Center

8. DIRECT CONTACT APPLICATION less stray radiation produce a more uniform pattern of heating deep in the tissues. NON – CONTACT APPLICATION Reflection at the air-skin interface occurs frequently Occasionally generating unacceptably intense stray radiation. METHODS OF APPLICATION

9. REFLECTION REFRACTION ABSORPTION PENETRATION TRANSMISSION PHYSICAL BEHAVIOUR OF MWD

10. Microwaves with a frequency of 2450MHz penetrate 1.7cm in muscle and skin , and 11.2cm in fat and bone . Superficial tissues moderately heated, achieve a maximum temperature within five to ten minutes, after which local vasodilatation prevents further warming . THERMAL MECHANISM OF MWD

11. RELIEF OF PAIN BY PAIN GATE MECHANISM REDUCTION OF MUSCLE SPASM BY STIMULATION OF SECONDARY NERVE ENDINGS. REDUCTION OF INFLAMMATION BY INCREASE IN BLOOD SUPPLY. THERAPEUTIC EFFECTS OF MWD

12. 4. To promote healing of open skin by increase in circulation Control the chronic infection by increasing the circulation. Fibrosis: heat increase the extensibility of fibrous tissues such as tendons, joint capsules and scars THERAPEUTIC EFFECTS OF MWD

13. Musculoskeletal disorders : Sprain- strain – muscle and tendon tear – degenerative joint disease- joint stiffness in superficial joints- capsular lesions. 2. Superficial inflammatory or infective conditions : Tenosynovitis – bursitis – Synovitis – infected surgical incisions – carbuncles – abscess. INDICATIONS OF MWD

14. Over malignant tissues. Over ischemic tissues. Moderate and excessive edema. Over wet dressings and adhesive tapes. Metal implants. Pacemaker. Over growing bone. CONTRAINDICATIONS OF MWD

15. Hemorrhage. Tuberculosis joints. Impaired thermal sensation. Unreliable patients. Recent radiotherapy. Hypersensitivity to heat. Acute infection or inflammation. CONTRAINDICATIONS OF MWD

16. Venous thrombosis or phlebitis. Pregnancy: heat applied to pelvis or hip in pregnancy may cause hemorrhage or miscarriage. Acute dermatological conditions. Severe cardiac conditions. Blood pressure abnormalities.

17. The eyes: cause cataract. Obesity: with 2450MHz microwave, there is danger of producing an excessive heat in the subcutaneous fat layer. PRECAUTION & DANGER

18. Duration of treatment 20 minutes is the optimum. Intensity : the patient should feel mild and comfortable warmth. Frequency : daily or on alternating day. Dosage of MWD

19. Thank you ….