Deflection simulation for a needle adjusted by the insertion orientation angle and axial rotation during insertion in...

During the process of percutaneous puncture, a medical needle with a beveled tip is usually inserted into a multilayered soft tissue, which contains a muscle layer, before it reaches the target. The robot-assisted needle insertion technology will help brachytherapists to perform high-accuracy seed implantation. To guide the automatic needle insertion, a mechanics-based model to simulate needle deflection caused by the asymmetric cutting force during insertion in the muscle-contained double-layered tissue is developed. The model is driven by the anisotropic and inhomogeneous interaction forces, which are updated off-line according to the tip's position and pose and are independent of the real-time data feedback. The parameterized insertion orientation angle and 180° axial rotation are introduced in the simulating process as the control inputs of the needle to adjust the needle deflection. Simulations and experiments confirm that the cooperative control of the insertion orientation angle and 180° axial rotation can steer the needle towards to any desired target in the reachable region of the tip. The results show that the proposed approach can successfully predict the needle deflection in the muscle-contained double-layered tissue. This work will be useful for a needle automatic control strategy design. Graphical abstract.