A hyfrecator is a low-powered medical apparatus used in electrosurgery on conscious patients, usually in an office setting. It is used to destroy tissue directly, and to stop bleeding during minor surgery. It works by emitting low-power high-frequency A.C. electrical pulses, via an electrode mounted on a handpiece, directly to the affected area of the body. The amount of output power is adjustable, and the device is equipped with different tips, electrodes and forceps, depending on the electrosurgical requirement.
The word Hyfrecator® is a portmanteau brandname derived from “high-frequency eradicator.” The device was originally introduced with this name in 1940, by the Birtcher Corporation of Los Angeles. [1] However, a number of manufacturers now produce "Hyfrecators". The name "hyfrecator" has since come to be used generically (like the once- tradenamed "aspirin") to refer to any dedicated non-ground-return electrosurgical apparatus.
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The hyfrecator differs from other electrosurgical devices primarily in being low-powered and not intended for cutting tissue, or for use in other than conscious patients. The reason is that the hyfrecator does not use a dispersive return pad or "patient plate", and thus either passes a very low-powered current between forceps tips (bipolar output), or else between a single pointed metal electrode probe, and the patient, with only the patient's self-capacitance providing a current sink (this is equivalent to considering displacement current to be the return current).
In the latter mode, the patient must sit or lie on an insulated table, much as in the case with objects to be charged electrostatically with high-voltage D.C. (as from a Van de Graaff generator, for example). Stray ground paths between the patient and foreign conductors (such as a metal table leading somewhere to earth-ground) can offer another capacitative reservoir besides the patient, and burns may thus result from current passing between patient and the earth-ground. For this reason, hyfrecation and all non-ground-pad electrosurgery is performed only on conscious patients who would be aware of the burn and discomfort from an unwanted earth-ground path. (In types of electrosurgery which do employ a ground pad, the ground-pad path serves as such a low resistance ground to the machine that extraneous other paths become unimportant, and so with proper precautions these methods can, and often are, used on anesthetized patients).
Because hyfrecation is a low-power modality, it can be used in some situations (such as very small nevus removal or skin tag removal) without local anaesthesia. In many other uses to destroy larger lesions, a local anesthetic injection or regional nerve block is used. The pain from hyfrecation is due to the burning of tissue, and the pain of electrical current is absent, due to the high (radio) frequency which does not affect discharge of nerves.
Although the hyfrecator is not used primarily to cut tissue, it may be used in a secondary capacity to control bleeding, after tissue is cut by a standard surgical scalpel, under local anesthesia. An example is the standard method of electrodesiccation and curettage used by dermatologists to destroy skin cancers.
Hyfrecators are used in two principal modes: