DIATHERMY MISS HIRA JABEEN

What is DIATHERMY Diathermy, from the Greek meaning "through heating” The use of non-ionizing electromagnetic energy from the radio-frequency spectrum as therapeutic agent

Types of Diathermy Long wave - Longest wavelength 300 – 30 m - Most penetrating - No longer utilized due to high potential of causing burns and interference with radio transmissions Shortwave Microwave

SHORTWAVE DIATHERMY

Deep heating modality Frequency - 27.12 MHz Wavelength - 11 m Description : High-frequency electrical currents Radio waves pass through the tissues cause molecular vibration results in deep heating capable of heating large volumes of tissues Causes both thermal and non thermal effects

Continuous vs Pulsed SWD

Production

Production

Production

Production

Production

Types of Shortwave Diathermy Induction Field Capacitive Field

Induction Field Diathermy Places the patient in the electromagnetic field Current flowing within the coil produces a rotating magnetic field Magnetic field produces eddy currents in the tissues Eddy currents cause friction that produce heat Selectively heats muscle Also referred to as: – Magnetic field diathermy

Capacitive Field Diathermy Uses the patient’s tissues as a part of the circuit The tissues’ electrical resistance produces heat Selectively heats skin – Muscle is heated via conduction from the adipose Also referred to as “condenser field diathermy”

TYPES OF ELECTRODES Flexible pads: consist of metal electrode encased in rubber and produce an electrostatic field.

TYPES OF ELECTRODES Space plates: consist of a rigid metal electrode encased in a Perspex cover electrostatic field.

TYPES OF ELECTRODES Coil or cable electrode: consists of a wire with plugs at either end creates electromagnetic field.

TYPES OF ELECTRODES The monode : flat, rigid coil encased in plastic cover electromagnetic field.

TYPES OF ELECTRODES The diplode : or drum electrode consists of a flat coil electrode encased in a Perspex cover with two wings electromagnetic field

Effects on Tissues Ionic motion Dipole rotation Molecular distortion

Physiological effects Does not stimulate sensory and motor nerves Shorter the duration lesser the effect on nerves Shortest duration impulses used 0.01ms High freq current has freq of more than 500kHz, provides one million impulses/sec No discomfort , no muscle contraction Evenly alternating so no danger of chemical burn But intensity can be increased to gain thermal effects

Physiological effects Physiological effects by heat: Inc metabolic activity Inc blood supply Effects of heating on nerves Indirect effects of heating Muscle relaxation General rise in temp Fall in BP Inc activity of sweat glands

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