The high-frequency electrosurgical knife itself must have a very perfect and reliable safety system, which is to ensure the safety of patients and medical personnel of the most basic conditions. Therefore, the high-frequency electrosurgical knife should be strictly tested and inspected one by one before leaving the factory, and even repeated many times. Users should also establish appropriate recurrent testing means to ensure that the knife's various safety indicators are always maintained in the International Electrotechnical Society and May 1995 release of China's high-frequency knife standards (i.e., IEC601-2-2, GB9706.4 and GB9706.1) within the scope of the provisions. The safety requirements of high-frequency generator and the necessary safety guarantee system are summarized as follows: (a) the output must be completely suspended, that is, the high-frequency high-voltage output portion of the high-frequency generator should be strictly isolated from the chassis (earth) and the power supply (utility). The output port (electrode) on the ground and power supply, not only the insulation resistance should be very large (& gt; 100MΩ), and in the application of the part connected to the ground distribution capacitance should be sufficiently small (& lt; 100pF), but also have to withstand about 6000V AC test voltage test. High-frequency generator output once the suspension is poor, high and low-frequency leakage current will increase rapidly, easy to burn or even life-threatening. For this reason, high-frequency knife should also have leakage and moisture resistance. Otherwise, once the moisture is bound to affect the degree of suspension of the knife output. (B) the metal chassis of the knife should be reliably grounded, that is, the ground of the power supply should really be connected to the earth, and the connection resistance between the ground point and the machine should be less than 0.2 Ω (even the power supply cable ground wire, including), in order to prevent the chassis and the protection of the ground point of the suspension of the electric charge, increasing the risk of electric shock and the machine to the outside world of the high-frequency radiation. (C) between the power grid and the enclosure (grounding wire) must be able to withstand 1500V withstand voltage. Chassis to ground leakage current should be less than 0.1mA, in order to ensure that the utility (low-frequency) and the chassis is well isolated to prevent electric shock. (D) low-frequency current is very harmful, excessive low-frequency leakage current will produce serious stimulation of the patient or even death. (E) high-frequency leakage current must be less than 150mA. high-frequency leakage current refers to the two output electrodes of the scalpel to the ground of the radiation current, the surgery has no effect on the patient can cause burns and environmental pollution. (F) high-frequency scalpel main carrier frequency (base wave) should be between 0.3 ~ 5MHz. It should not be too low or too high (full-suspension electrosurgical knife is generally between 0.4 and 0.8MHz). If it is too low, it will produce low-frequency stimulation; if it is too high, it will have serious high-frequency radiation. (G) In any case, the output power of high-frequency electrosurgical knife shall not exceed 400 W. Excessive power will cause damage to the patient. (viii) The output power of high-frequency electric knife should be as stable as possible. In the power supply voltage fluctuations and load changes, the output power should still be within the prescribed range. Otherwise, when the operation, either cut, coagulation effect is poor, or coke sticky tissue, and even serious burns patients. (ix) high-frequency scalpel output waveform must be stable, its base wave should be relatively pure sine wave. Otherwise, it is easy to cause output power instability, increase high-frequency leakage current or generate low-frequency work current. (J) the handle of the knife and connecting cable appearance of the electrode voltage should be able to withstand 3000V (AC RMS) and 2 times the high-frequency knife open-circuit output voltage test. Otherwise, there is a risk of burns due to leakage of electricity to the operator and (or) the patient. (XI) a control action should only be able to start a surgical electrode of the scalpel. Otherwise, the unused tip will cause accidental burns to the operator or patient with whom it is in contact. Some old-fashioned electrosurgical knife, a control action can start more than one surgical electrode (head) output at the same time. In this case, special attention should be paid to: do not connect the unused tip to the machine. If it is connected, it should be placed in an insulated container. Never leave them lying around. (xii) The hand switch and foot switch should preferably be of the sealed type. In this way, can prevent water, blood or disinfectant into the switch and make the electric knife misoperation burns the person concerned. (XIII) pole plate area should be large enough, preferably paste type. Ensure that the current from the patient's muscles back to the machine in the human body and the pole plate in contact with the density as low as possible (<0.02A/cm2=.). (XIV) neutral electrode (pole plate) disconnection or impedance is too large, the instrument should have sound and light alarm and cut off the output function. Prevent the break point or large impedance point to produce power consumption caused by burns or fire. (xv) The output power should be increased with the increase in the set value and decreased with the decrease in the set value. Prevent unwanted power changes that cause danger when adjusting the setting. (xvi) When cutting and condensing are started at the same time, the power output should be prohibited or only the mode with less power (e.g. condensing) should be output. Prevent excessive power from being added to the patient due to misuse. (XVII) cut, coagulation start, there should be a clear sound and light prompts to remind the operator attention. (xviii) High-frequency electric knife in cardiac surgery use, will often encounter the use of defibrillator. CF type electric knife application part should be able to withstand 2kV defibrillation voltage shock. (xix) The generator can be started at any setting for a long time in open circuit, and can be short-circuited many times without affecting the performance and safety of the machine.
(xx) The output shall not be increased by more than 20% at any setting when the power supply is restarted or started to be restarted. Prevent excessive power suddenly added to the patient. (XXI) The output under the rated load should correspond to the set position and the power deviation should be ≤20%. The full power and half power curves under different loads should also deviate from the specified values by ≤20%. (XXII) The working voltage of the hand control switch should be ≤12V; the working voltage of the foot switch should be ≤24V. (XXIII) The output circuit should be strung with a high-voltage capacitor of not less than 5000pF. The DC impedance of the output electrode (pair) should be much larger than 2MΩ to prevent low-frequency output. (XXIV) the machine should be moisture-proof internal treatment, the casing should be able to prevent liquid (when tipped over) immersed in the machine. Ensure the insulation and isolation of the instrument.