Ultrasonic Power Based On Ultrasonic Scalpel

Ultrasonic technology has been widely used in medical field.As a kind of minimally invasive surgery,ultrasonic knife surgery has the specific advantage.Ultrasonic knife has already achieved "fast cutting,fast congulating",having functions of cutting and coagulation hemostasis,which greatly facilitates the operation of medical personnel.Ultrasonic power is an important part of the whole ultrasonic knife surgery system.Ultrasonic power supplies power for ultrasonic transducer,driving the ultrasonic transducer and ultrasonic knife work.During the surgery,the impedance of the ultrasonic transducer has great changes,bringing a lot of difficulties to the design of ultrasonic power supply.This paper is devoted to the design solution of low cost and high reliable ultrasonic power supply,analyzing and solving the key technology existing in the ultrasonic power supply.Combined with the medical instrument specifications,the impedance change of ultrasonic transducer is analyzed and transformer matching isolating circuit is designed in this paper.Fequency offset of ultrasonic transducer happens in the process of work.In order to solve the problem of series frequency tracking of ultrasonic transducer,this paper proposes an improved scheme based on hardware phase locked loop and optimizes the lock time of phase locked loop.In order to achieve good operation effect,the constant current output is used in the ultrasonic power supply.This paper presents constant current control technology of a half bridge resonance circuit.In view of the design of the project,a platform is constructed in the lab and a detailed test is carried out.The frequency automatic tracking performance,constant current control performance and stability of the ultrasonic power are tested.