Preliminary Simulation and Optimization Design of Ultrasonic Harmonic Scalpel

In this paper, the structure and vibration mechanism of the ultrasonic harmonic scalpel are studied theoretically. According to the one-dimensional longitudinal vibration theory of elastic rod and finite element simulation method, the structure of ultrasonic transducer and amplitude transformer are designed with the resonant frequency of 55.5 kHz and the output amplitude greater than 40 microns. Then, an axisymmetric cylindrical arbor structure was studied and optimized by the finite element method (FEM). Optimization includes reducing the diameter of the scalpel head and thickening the cylinder at the antinode of radial displacement, such that the radial vibration and the stress of the scalpel rod is reduced; finally, a simple simulation analysis of the three-dimensional structure with the scalpel head is carried out, the result shows that the structure of the asymmetry scalpel head can increase the radial vibration of the scalpel rod.