Background and objective

Percutaneous puncture with flexible needle has important value in clinical application for its low trauma and flexible path. However, it is difficult to guarantee accuracy and avoid obstacles in puncture process. Therefore, developing a viable path planning method is particularly important. In this research, the bending deformation law of flexible needles during puncture was studied and the puncture path was planned to provide a feasible method for clinical application of flexible needles.

Methods

According to the researchs that have been conducted, the path of the flexible needle in the tissue could be considered as a circular arc stitching. This research studied the calculation method of arc radius and obtained its actual value by the puncture experiments. Based on the arc model, the spatial transformation method of three-dimensional path planning was studied. In addition, a simplified particle swarm optimization (PSO) was applied into the process of path planning by changing the central angle of arc and the rotation angle of the needle body.

Results

The results of Experiment 1 showed that the path radius of the flexible needle pierced into gelatin prosthesis was influenced by four parameters, which were needle diameter, tip angle, puncture speed and the weight ratio of gelatin powder. As the needle diameter and tip angle increased, the radius of needle path tended to increase, but when the puncture speed and gelatin mass ratio increased, the radius of needle path decreased. The results of Experiment 2 showed that the distances of needle tip apart from target point were 3.2 mm (barrier-free experiments) and 1.8 mm (obstacle experiments).

Conclusions

This research links the intelligent algorithm with the flexible needle puncture tissue process, which has high value in future clinical application. By setting the correct boundary conditions and parameters, the flexible needle can be planned to reach the target point accurately.

中文翻译：

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基于粒子群优化的临床灵活的穿刺路径规划。

背景和目标

柔性针经皮穿刺术由于其创伤小，路径灵活等特点在临床应用中具有重要的价值。然而，难以保证准确性并避免穿刺过程中的障碍。因此，开发可行的路径规划方法尤为重要。本研究研究了穿刺针在穿刺过程中的弯曲变形规律，并设计了穿刺路径，为穿刺针的临床应用提供了一种可行的方法。

方法

根据已经进行的研究，可以将柔性针在组织中的路径视为圆弧缝合。本研究研究了圆弧半径的计算方法，并通过穿刺实验获得了圆弧半径的实际值。基于弧模型，研究了三维路径规划的空间变换方法。此外，通过更改圆弧的中心角和针体的旋转角度，将简化的粒子群算法（PSO）应用于路径规划过程。

结果

实验1的结果表明，刺入明胶假体的柔性针的路径半径受四个参数的影响，这四个参数是针直径，尖端角度，穿刺速度和明胶粉的重量比。随着针直径和顶角的增加，针路径的半径趋于增加，但是当穿刺速度和明胶质量比增加时，针路径的半径减小。实验2的结果表明，针尖到目标点的距离为3.2mm（无障碍实验）和1.8mm（障碍实验）。

结论

本研究将智能算法与柔性穿刺组织过程相结合，在未来的临床应用中具有很高的应用价值。通过设置正确的边界条件和参数，可以计划柔性针精确地到达目标点。