The Research Of The Control System In Electrosurgical RF Energy Generator

Electrosurgical devices, also called Radio-Frequency Energy Generator, are themost common instruments in the operating theater. With100-year development, theirvarieties and functions are much wider, such as main vessel closure. Compared withtraditional surgical appliance, electrosurgical instrument can perform cutting andcoagulation simultaneously so as to reduce operation bleeding, make surgical visionclear and shorten the length of operation. Yet, since the value and duration of its outputenergy are generally subject to the subjective judgment of doctors according to theirown experience, it also brings along some side effects, such as causing thermal damagefor an over releasing of energy or the failure of sealing due to the inadequacy of energy.Besides, most of the domestic radio-frequency energy generator is power consumption,bulky and low level of digital.To solve those above problems, a kind of radio-frequency energy generator withsmart is developed hereby. The switching power supply with fast response and goodvoltage regulation was designed to instead of linear power. The push-pull class E poweramplifier was designed to substitute for the full-bridge switching power amplifier circuitand Class D amplifier for improving the output power and efficiency. The analogintegrated circuit as a control unit was replaced by a micro-controller.Thereby, in this thesis, discussed the control method of the Tissue Sealing andTissue Fusion. Also developed the specific control system which specialized applied tothose field. This system adapted the newly control chip and rapidly and efficientswitching power supply control. Combination of precise impedance detectiontechnology and circuit, this system will be more safety and more usability. This thesisare also studied the energy control method based on biological tissue impedancechange.The experiment results showed that this RF energy generator could satisfy themain technical index, the switching power supply could provide high-stability DC, theimpedance monitor could detect biological impedance information accurately, thepush-pull E class power amplifier could working efficiently.