Purpose

Planning a safe path for flexible catheters is one of the major challenges of endovascular catheterization. State-of-the-art methods rarely consider the catheter curvature constraint and reduced computational time of path planning which guarantees the possibility to re-plan the path during the actual operation.

Methods

In this manuscript, we propose a fast two-phase path planning approach under the robot curvature constraint. Firstly, the vascular structure is extracted and represented by vascular centerlines and corresponding vascular radii. Then, the path is searched along the vascular centerline using breadth first search (BFS) strategy and locally optimized via the genetic algorithm (GA) to satisfy the robot curvature constraint. This approach (BFS-GA) is able to respect the robot curvature constraint while keeping it close to the centerlines as much as possible. We can also reduce the optimization search space and perform parallel optimization to shorten the computational time.

Results

We demonstrate the method’s high efficiency in two-dimensional and three-dimensional space scenarios. The results showed the planner’s ability to satisfy the robot curvature constraint while keeping low computational time cost compared with sampling-based methods. Path replanning in femoral arteries can reach an updating frequency at \(6.4\pm 2.3\)Hz.

Conclusion

The presented work is suited for surgical procedures demanding satisfying curvature constraints while optimizing specified criteria. It is also applicable for curvature constrained robots in narrow passages.

中文翻译：

---

两阶段搜索方法在曲率约束下血管内导管插入术的路径规划

目的

规划柔性导管的安全路径是血管内导管插入术的主要挑战之一。现有技术中的方法很少考虑导管曲率约束和减少路径规划的计算时间，这保证了在实际操作过程中重新规划路径的可能性。

方法

在本文中，我们提出了一种在机器人曲率约束下的快速两阶段路径规划方法。首先，提取血管结构，并用血管中心线和相应的血管半径表示。然后，使用广度优先搜索（BFS）策略沿血管中心线搜索路径，并通过遗传算法（GA）进行局部优化以满足机器人曲率约束。这种方法（BFS-GA）能够遵守机器人的曲率约束，同时使其尽可能靠近中心线。我们还可以减少优化搜索空间，并执行并行优化以缩短计算时间。

结果

我们在二维和三维空间场景中证明了该方法的高效率。结果表明，与基于采样的方法相比，计划者能够满足机器人曲率约束，同时保持较低的计算时间成本。股动脉的路径重新规划可以达到\（6.4 \ pm 2.3 \） Hz的更新频率。

结论

提出的工作适合在优化指定标准的同时满足曲率约束条件的外科手术。它也适用于狭窄通道中曲率受限的机器人。