Study of a Dynamic Impedance Matching Method for Ultrasonic Bone Knife Transducer

Since the stability of the working performance of ultrasonic bone knife transducer is closely related to the dynamic impedance matching, this paper designs a dynamic impedance matching closed-loop control system. The dynamic impedance calculation model of ultrasonic bone knife transducer is established, and on this basis, the voltage, current true RMS value and dynamic impedance phase monitoring circuit and variable inductance adjustment circuit are designed during the working process of ultrasonic bone knife transducer, and the real-time calculation of impedance matching inductance is realized. The impedance matching closed-loop control system was also tested, and the experimental results show that the dynamic impedance matching method can satisfy the ultrasonic bone knife transducer working in a purely resistive state, and the steady state output amplitude of the current is significantly improved compared with that before the matching, which further lays down a foundation for the frequency tracking control of the ultrasonic bone knife transducer.