Diathermy
A medical and surgical technique involving the production of heat in a part of the body by high-frequency electric currents, to stimulate the circulation, relieve pain, destroy unhealthy tissue, or cause bleeding vessels to clot.
- Mechanism of Diathermy:
Diathermy uses very high frequencies of electrical current. This allows diathermy to avoid the frequencies used by body systems generating electrical current, such as skeletal muscle and cardiac tissue, allowing body physiology to be broadly unaffected during its use.
The radiofrequencies generated by the diathermy heat the tissue to allow for cutting and coagulation, by creating intracellular oscillation of molecules within the cells.
- Types of Diathermy:
a) Monopolar Diathermy: where electric current passes from one electrode near the tissue to be treated to other fixed electrode (indifferent electrode) elsewhere in the body.
Usually, this type of electrode is placed in contact with buttocks or around the leg.
b) Bipolar Diathermy: where both electrodes are mounted on same pen-like device and electric current passes only through the tissue being treated.
Advantage of bipolar electrosurgery is that it prevents the flow of current through other tissues of the body and focuses only on the tissue in contact.
This is useful in microsurgery and in patients with a cardiac pacemaker.