Needle Deflection Modeling and Preoperative Trajectory Planning During Insertion Into Multilayered Tissues

Percutaneous needle insertion is a widely used technique in needle-based intervention; however, it is difficult to achieve high targeting accuracy due to needle deflection and the boundary effect in multilayered tissues. This article presents a preoperative needle insertion trajectory planning method that includes needle deflection modeling, insertion angle correction, and needle trajectory optimization. The needle deflection model can predict the needle deflection with preoperatively obtained information, which includes tissue-specific parameters and the geometric/material properties of the needle. An insertion angle shift distribution model is obtained based on experimental data and is used to correct insertion angles at tissue boundaries. The needle trajectory optimization is based on the weighted sum of cost function and balances the assessment criteria, which include the trajectory length, the insertion angle, and the distance to critical structures, and determines the needle trajectory with the best performance. Experiments are conducted to demonstrate that with the proposed preoperative needle insertion trajectory planning method, a needle insertion trajectory with increased accuracy, desired insertion length, and safe distance to critical structures can be obtained.