Design and Performance Study of an Ultrasonic Bone Scalpel with Composite Horn Structure

Abstract

The ultrasonic bone scalpel was often used in all kinds of clinical orthopedic surgery as a new type of medical instrument. Based on the working theory of the ultrasonic bone scalpel and combined with the design method of a quarter wavelength transducer and horn, this study proposed an optimization design method for the ultrasonic bone scalpel with a composite horn structure. The structure of the ultrasonic bone scalpel was simplified, and its length was shortened. Finite element analysis, modal analysis, and harmonic response analysis were used to optimize the design of the ultrasonic bone scalpel. The performance of the ultrasonic bone scalpel was explored through impedance analysis, amplitude measurement, temperature measurement, and cutting tests, and the feasibility of the design was verified through torque analysis. The results showed that when the torque force was 4.0 N, the resonance frequency of the ultrasonic bone scalpel was 30,540 Hz, and the maximum amplitude of the ultrasonic bone scalpel could reach 62 μm. After spray cooling, the maximum surface temperature of the rear end cover was reduced from 51.8 to 36.3 ℃, the maximum surface temperature of the composite horn was reduced from 71 to 45.3 ℃, and the maximum surface temperature of the cutter head was reduced from 101 to 46.1 ℃, demonstrating a good cooling effect. Under 89 Voltage, the optimal cutting force for cutting chicken leg bones was 0.1 N, the optimal cutting force for cutting pork ribs was 0.3 N, and the cutting process showed tissue selectivity.