The principle for electrosurgical unit

High-frequency electrosurgery unit is an electrosurgical instrument that replaces mechanical scalpels for tissue cutting.

The high-frequency high-voltage current generated by the effective electrode tip heats the tissue when it is in contact with the body, so as to achieve separation and coagulation of the body tissue, thereby achieving the purpose of cutting and hemostasis.


There are two main working modes of high-frequency electrosurgical knife: monopolar and bipolar.


Monopolar Mode: In monopolar mode, a complete circuit is used to cut and cure tissue. The circuit consists of a high-frequency generator, a negative plate, a connecting wire and electrodes in a high-frequency electric knife. The heating effect of high-frequency electrosurgery, which can destroy the diseased tissue, is not caused by the heating electrode or the cutter head, just like electric cautery. It concentrates high current density high frequency current and destroys tissue at the point of contact with the active electrode tip. Coagulation occurs when the temperature of the tissue or cells in contact with the active electrode rises so that the proteins in the cells denature. This precise surgical effect depends on the waveform, voltage, current, tissue type, and shape and size of the electrodes.


Some of the high-frequency electrosurgical knives used by doctors for diagnosis are very low in current and density, so the patient’s negative plate cannot be used, but most high-frequency electrosurgery uses a large current, so the patient needs a negative plate. For ground systems, the risk of burns is greater than for insulated output systems.


Bipolar mode: its scope of action is limited to both ends of the tweezers, and the degree of damage and influence of the tweezers is much smaller than that of the monopole. Suitable for occlusion of small blood vessels (diameter < 4 mm) and fallopian tubes. Therefore, bipolar coagulation is mainly used in brain surgery, microsurgery, five major features, obstetrics and gynecology, hand surgery, etc. The safety of high-frequency electrotome bipolar coagulation is gradually being recognized, and its application range is gradually expanding.

Post time: Jan-26-2022