A dual-frequency ultrasonic aspirator and its fundamental performance in biological soft tissue removal

An ultrasonic aspirator is an ultrasonic surgical instrument that utilizes cavitation and mechanical effects to remove soft biological tissue. Owing to the advantages of selective tissue removal and rapid postoperative recovery, this instrument has been extensively applied in clinical procedures, including liver and brain surgeries. In our previous study, a dual-frequency ultrasonic aspirator was proposed, which enhances inertial cavitation by disrupting the stable oscillatory behavior of cavitation bubbles, thereby improving surgical efficiency. In the present study, the performance of the designed dual-frequency ultrasonic aspirator was systematically investigated. Finite element modeling and modal analysis were conducted to identify its second- and sixth-order longitudinal vibration modes, and frequency-domain response analysis was employed to characterize the dual-frequency ultrasonic vibration. The vibration response of the ultrasonic aspirator was measured using a laser Doppler vibrometer, which confirmed the successful generation of dual-frequency ultrasonic vibration. Furthermore, a frequency response analyzer was used to examine the influence of dual-frequency ultrasonic vibration on frequency shift. Cavitation phenomena were visualized using a high-speed camera. The results demonstrate that dual-frequency excitation effectively enhances inertial cavitation compared with single-frequency ultrasound. Liver tissue removal rate experiments indicate that the dual-frequency ultrasonic aspirator achieves higher tissue removal efficiency. Moreover, liver tissue removal quality experiments confirm that the device maintains favorable removal quality and safety while improving efficiency. Finally, tissue removal behavior experiments provide preliminary insights into the role of cavitation effects in liver tissue removal.