DIATHERMY Diathermy Therapeutic treatment commonly prescribed for muscular

DIATHERMY

Diathermy Therapeutic treatment commonly prescribed for muscular and joint associated pains.

INTRODUCTION v. The term ‘diathermy’ means ‘through heating’ or producing deep heating directly in the tissues of the body. ‘ Dia’ ‘thermy’ through heat or temperature v It stimulates the circulation, relieve pain, enhances rate of recovery of healing the tissue.

PRINCIPLE OF DIATHERMY v. Before injury, the dipole molecules of the body tissue arranged on the basis of polarity v. When the tissue is damaged the dipoles distribution become irregular and deviates from polarity based arrangement.

PRINCIPLE OF DIATHERMY v. Under the influence of an electric field , they rotate according to the polarity of their charge in the direction of the field lines and get rearranged and tends to acquire its previous stage of polarity.

HEAT AND TISSUE INTERACTION

BENEFITS OF DIATHERMY Ø Intense heat delivered provides pain relief and better flexibility ØReduces inflammation ØImproves circulation ØAccelerate healing

Surgical Diathermy Machine § It is a dedicated medical therapeutic equipment used by surgical departmental doctors for the purpose of cut, coagulate, desiccate, or fulgurate tissue. § Two modes are used as desired by Doctors(i) Monopolar (ii) Bipolar

Block Diagram of Surgical Diathermy

Electro -Surgery Techniques • Mono-polar technique • Bi-polar technique

Monopolar electro surgery • Monopolar electro surgery is the admittance of the HFAC from the diathermy machine via an active electrode through the patient body tissues and then returned back to the diathermy machine via a dispersive electrode (patient return pad)

Mono-polar technique

Some Basics of Monopolar Surgery Ø Diathermy currents (HFAC) may be generated by transistor circuits and may include a range of protection. Ø The frequencies used are typically in the range 0. 5 to 3 MHz. Ø Most versions have power output up to a few hundred watts. Ø Higher power necessary for urology applications where the surgery often takes place under water (in the bladder). Ø Low power versions exist, sometimes called hyphenators, for excision of warts, polyps, and skin flaps.

Bipolar electro surgery �Bipolar electro surgery is the admittance of the HFAC from the diathermy machine down one prong of a bipolar forceps through the tissue that has been placed between the forceps tips and returned to the diathermy machine via the second prong. �Bipolar diathermy does not require a dispersive electrode (patient return pad).

Bi-polar technique

Some Basics of Bipolar Surgery �Diathermy currents may be generated transistor circuits and may include a range of protection and monitoring systems. �The frequencies used are typically in the range 0. 5 to 3 MHz. �Bipolar systems are available in which the heating currents only flow between the two tips of special forceps. �Bipolar systems are useful for fine work and when the patient has a pacemaker which might malfunction in the presence of the very large circulating high- frequency current.

Electro-Surgery Unit (ESU) • An ESU consists of basically a high frequency power oscillator: • Spark-gap oscillator: Generates damped high frequency current which is specifically suitable for the coagulation of all kinds of tissues. • Solid-state oscillator: Generates un-damped high frequency current which is suitable for making clean cutting.

Solid-State ESU • The heart of solid-state ESU is the logic and control part which produce the basic signal and provides various timing signals for the cutting, coagulation and haemostatic modes of operation. • In the cutting it delivers 400 W in 500 Ω load at 2000 V. • In the coagulation it delivers 150 W. • The output circuit in ESU is generally isolated and carefully insulated from low frequency primary and secondary voltage by means of capacitors.

ESU Electrodes

Types of ESU Electrodes • Active Electrode • Passive Electrode

Active Electrodes • Electrodes are connected to the RF power generator. • Switching on the high frequency current can be done with a finger-tip switch in the electrode or a foot switch. • Small size (thickness in mm (1 mm) and wideness till 10 mm).

Active electrode for coagulation

Active Electrode Resistance �The amount of power delivered to the tissue for a given ESU voltage depends on the active electrodeto-skin resistance RE. �RI: Internal resistance of active electrode �RE: active electrode-to-skin resistance �RB: Body resistance �RR: Return electrode resistance

Passive (Neutral, Return) Electrode �The function of the patient return electrode is to remove current from the patient safely. �A return electrode burn occurs when the heat produced, over time, is not safely dissipated by the size or conductivity of the patient return electrode. �Two points are of practical importance: (i) Sufficiently large contact area. (ii) High electrical conductivity between the body and electrode.

Passive (Neutral, Return) Electrode

Effects on Body Tissue • • Cutting Coagulation Fulguration Desiccation

Cutting/Vaporization: ØHigh current concentration at active electrode causes intense heat in tissue (above 100 c).

Coagulation �Coagulation is the process by which blood forms clots. Every damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel.

Fulguration �Fulguration, also called electrofulguration, is a procedure to destroy tissue (such as a malignant tumor) using a high-frequency electric current applied with a needlelike electrode.

Desiccation • Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container.

TYPES OF DIATHERMY 1. SHORT WAVE DIATHERMY 2. LONGWAVE DIATHERMY 3. MICROWAVE DIATHERMY 4. ULTRASOUND DIATHERMY 5. LASER DIATHERMY

SHORTWAVE DIATHERMY Ø Shortwave diathermy uses high-frequency electromagnetic energy to generate heat. Ø It may be applied in pulsed or continuous energy waves. Ø It is used to treat pain from sinusitis, kidney stones, and pelvic infections. Ø It is effective for conditions that cause pain and muscle spasms.

Shortwave Has Three Main Frequencies: v 27. 12 MHz, wavelength 11 M (most common used one). v 13. 56 MHz wavelength 22 M. v 40. 68 MHz 7. 5 M.

MICROWAVE DIATHERMY Ø Microwave diathermy uses microwaves to generate heat in the body. Ø It can be used to evenly warm deep tissues without heating the skin. Ø Since it can’t penetrate deep muscles, it is best suited for areas that are closer to the skin, such as shoulders.

ULTRASOUND DIATHERMY Ø Ultrasound diathermy uses sound waves to treat deep tissues. Ø Heat is generated by the vibration of the tissue. Ø This promotes blood flow into the area. Ø It is used for many types of musculoskeletal sprains, strains, and fractures.

LONGWAVE DIATHERMY Ø Long wave diathermy is based on capacitor field method. ØIt can work in heavy voltage fluctuation ØLong wave can be used as an alternative for shortwave diathermy applications. Ø it is portable and light weight.

DIATHERMY PROVIDES RELIEF IN: Ø ARTHRITIS ØBACK PAIN ØMUSCLE SPASMS ØNEURALGIA ØMYOSITIS ØSPRAINS AND STRAINS ØTENDONITIS ØBONE INJURIES ØBURSITIS

UNWANTED EFFECTS OF DIATHERMY Ø The electromagnetic energy used in diathermy can cause extreme heat in metal devices such as bone pins, dental fillings, and metal sutures causing burns Ø During diathermy treatment, the patient becomes a part of the electrical field. Touching a bare metal object, such as a cabinet, during diathermy can cause a shock or burn.

RISKS ASSOCIATED WITH DIATHERMY Diathermy should be avoided in following cases: Ø Ø Ø Ø implanted metal devices peripheral vascular disease tissue with restricted blood supply (ischemia) cancer bleeding disorders , wound dressings severe heart, liver, or kidney conditions pregnancy