Abstract
Needle insertion of thin tissues is a crucial procedure in invasive biomedical operations. Reducing the interaction force during needle insertion could yield benefits such as avoiding tissue damage caused by overstretch and improving the insertion accuracy by decreasing the target point deformation. Vibration-assisted needle insertion possesses the advantages of low injury risk, unrestricted by incision and balanced insertion controllability and efficiency. However, the mechanism of vibration assistance for thin tissue insertion is unclear, and how to select appropriate insertion parameters to reduce the interaction force effectively requires further investigation. This paper focuses on the vibration-assisted needle insertion method of thin tissues to reduce the interaction force. A comprehensive force model is established based on the overall consideration of the coupled, time-varying and phased needle-tissue mechanical interaction behaviors and the geometrical characteristic of tissue. The influence of vibration is analyzed and modeled based on the vibration-enhanced stress concentration and the time-averaged effect of friction. A vibration-assisted needle insertion experimental setup is established, and thin tissue insertion tests are carried out to investigate the influences of insertion parameters on different kinds of interaction forces and validate the theoretical model. The results show that the fracture force and friction force increase when the insertion velocity is raised. The fracture force monotonically decreases with both the vibration frequency and amplitude, while the friction force reduces with a smaller velocity ratio. The study provides valuable insights for reducing the interaction force of thin tissue insertion.
