基于虚拟弹簧模型的柔性针穿刺仿真研究

Study on Flexible Needle Insertion Simulation Based on Virtual Spring Model

在分析柔性针受力和挠曲的基础上,建立二维空间上柔性针穿刺软组织的虚拟弹簧模型,得到针体和针尖轨迹的数学模型。使用Matlab工具软件对针尖轨迹在不同情况下进行仿真。仿真实验结果表明,柔性针弹性变形量对针尖走向影响较小,影响针尖走向的主要因素是纵向控制坐标和针座与水平线初始夹角,且两者的叠加效应最终影响柔性针走向,可以为机器人辅助针穿刺操控提供理论基础,结合软组织变形研究,能够实现柔性针穿刺的轨迹规划和避障运动。

Based on the analysis of needle forces and deflection, flexible needle insertion into soft tissue is modeled with virtual spring. The trajectory of the flexible needle body and tip is simulated with Matlab software in the different cases. The simulation results show that the elastic deformation of the flexible needle does not affect needle tip trajectory evidently, and the main factors of effects on needle tip trajectory are the controlling coordination of lengthways direction and the initial angle between needle base and level line. Considering the soft tissue deformation during flexible needle insertion, the theories proposed can be used in robot-assisted needle insertion steering, path planning and obstacle avoidance can be realized.