Percutaneous needle insertion is a widely used technique in needle-based interventions such as biopsy and ablation. However, it is difficult to achieve high targeting accuracy due to needle deflection and the boundary effect in multilayered tissues.  

Researchers from the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences proposed a preoperative needle insertion trajectory planning method that includes needle deflection modeling, insertion angle correction and needle trajectory optimization.  

Their study was published in IEEE/ASME Transactions on Mechatronics. 

This needle deflection model could predict the needle deflection with preoperatively obtained information, contains tissue-specific parameters and the geometric/material properties of the needle. 

In order to correct insertion angles at tissue boundaries, the influence of boundaries between layered tissues was took into consideration, researchers designed an insertion angle shift distribution model, which was obtained based on experimental data.  

In addition, the needle trajectory optimization was based on the weighted sum of cost function and balances the assessment criteria, which including the trajectory length, the insertion angle, and the distance to critical structures, and determines the needle trajectory with the best performance.  

Their experiments have been conducted and demonstrated that with the proposed preoperative needle insertion trajectory planning method, a needle insertion trajectory with desired insertion length and insertion angle and safe distance to critical structures could be obtained, and the needle insertion accuracy increased from 4.30 mm to 0.97 mm in gelatin model and from 5.15 mm to 1.40 mm in animal tissue model as well.  

Media Contact: 
ZHANG Xiaomin 
Email: xm.zhang@siat.ac.cn