Electrosurgery System has become an indispensable device in the operating room. In a narrow sense, ESU refers to a high-frequency electrotome that performs cutting and hemostasis directly by using the thermal effect caused by high-frequency and high-voltage alternating current through the tissue. In a broad sense, ESU refers to the surgical equipment for cutting, separating and hemostasis of tissues by using high-frequency electric energy, including high-frequency electric knife, radiofrequency knife, ion knife, etc.

Electrosurgical equipment is an important equipment in surgery, and it is also a kind of equipment with high risk, so it is necessary to be familiar with some characteristics of these equipment.

There are great differences in the working principles of hf electrotome, RF knife and ion knife:

(1) High-frequency electric knife: the host machine emits high-frequency current to form an electric circuit through the electrolyte inside the human body, and the place where the surgical electrode contacts the tissue generates heat energy, so as to achieve the effect of cutting or hemostasis;

(2) radio frequency knife: the use of radio waves generated by radio frequency current through the human body, so that the electrolyte ions in the human body do high-speed reciprocating motion, ion friction energy, so that the cell molecular bond fracture, so as to achieve the effect of cutting tissue;

(3) Ion knife: The radio frequency electric field ionizes the atoms in the tissue, forming a group of "plasma" substances (including free electrons, ions, neutral chemical groups and other neutral substances), the plasma is accelerated under the action of the applied electric field, can cause the molecular bond of the tissue cells to break, so that the cell disintegration, achieve the cutting effect.