THERAPEUTIC DIATHERMY EQUIPMENT

Typical Number in Hospital: 12

Cost Bands: 3,4

References: 4

Diathermy refers to processes which produce deep heating of the tissues. Surgical diathermy used in surgery is not really diathermy at all and should be called by its proper name, electrosurgery. True diathermy is used in physiotherapy for the treatment of strains and sprains resulting in chronic inflammation, and for the relief of pain. There are three processes used to cause diathermy.

1. Shortwave diathermy. Radio frequency energy (usually 27 MHz) is applied between two metal plates so that part of the energy is absorbed in the tissue. This causes heating throughout the limb or other area under treatment.

2. Microwave diathermy. Radio-frequency energy (usually 2450 MHz) is directed at the body from an aerial. The process is similar to microwave cooking except that the microwaves are applied from one side only. Thus most heating occurs at the skin surface and diminishes with distance into the tissue.

3. Ultrasonic diathermy. Ultrasonic energy between 1 and 3 MHz is applied directly to the skin, or with a patient in a bath, relying on the absorption of ultrasound in tissue. Using intensity levels of between 1 and 3 W/cm2 mild heat is generated internally which is particularly useful in the treatment of inflammation of joints and tendons.