当前位置: X-MOL 学术Int. J. Robot. Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Enhanced real-time pose estimation for closed-loop robotic manipulation of magnetically actuated capsule endoscopes
The International Journal of Robotics Research ( IF 9.2 ) Pub Date : 2018-06-25 , DOI: 10.1177/0278364918779132
Addisu Z Taddese 1 , Piotr R Slawinski 1 , Marco Pirotta 2 , Elena De Momi 2 , Keith L Obstein 1, 3 , Pietro Valdastri 4
Affiliation  

Pose estimation methods for robotically guided magnetic actuation of capsule endoscopes have recently enabled trajectory following and automation of repetitive endoscopic maneuvers. However, these methods face significant challenges in their path to clinical adoption including the presence of regions of magnetic field singularity, where the accuracy of the system degrades, and the need for accurate initialization of the capsule’s pose. In particular, the singularity problem exists for any pose estimation method that utilizes a single source of magnetic field if the method does not rely on the motion of the magnet to obtain multiple measurements from different vantage points. We analyze the workspace of such pose estimation methods with the use of the point-dipole magnetic field model and show that singular regions exist in areas where the capsule is nominally located during magnetic actuation. As the dipole model can approximate most magnetic field sources, the problem discussed herein pertains to a wider set of pose estimation techniques. We then propose a novel hybrid approach employing static and time-varying magnetic field sources and show that this system has no regions of singularity. The proposed system was experimentally validated for accuracy, workspace size, update rate, and performance in regions of magnetic singularity. The system performed as well or better than prior pose estimation methods without requiring accurate initialization and was robust to magnetic singularity. Experimental demonstration of closed-loop control of a tethered magnetic device utilizing the developed pose estimation technique is provided to ascertain its suitability for robotically guided capsule endoscopy. Hence, advances in closed-loop control and intelligent automation of magnetically actuated capsule endoscopes can be further pursued toward clinical realization by employing this pose estimation system.

中文翻译:

增强型实时姿态估计,用于磁驱动胶囊内窥镜的闭环机器人操作

用于胶囊内窥镜机器人引导磁驱动的姿势估计方法最近实现了轨迹跟踪和重复内窥镜操作的自动化。然而,这些方法在临床应用过程中面临着重大挑战,包括磁场奇点区域的存在(系统的准确性会降低)以及胶囊姿态的精确初始化的需要。特别是,如果任何利用单一磁场源的姿态估计方法不依赖于磁体的运动来从不同的有利位置获得多个测量值,则该方法都存在奇点问题。我们使用点偶极磁场模型分析了此类姿态估计方法的工作空间,并表明奇异区域存在于磁驱动过程中胶囊名义上所在的区域中。由于偶极子模型可以近似大多数磁场源,因此本文讨论的问题涉及更广泛的姿态估计技术。然后,我们提出了一种采用静态和时变磁场源的新型混合方法,并表明该系统没有奇点区域。所提出的系统在磁奇点区域的精度、工作空间大小、更新率和性能方面经过实验验证。该系统的性能与先前的姿态估计方法一样好或更好,不需要精确的初始化,并且对磁奇点具有鲁棒性。利用所开发的姿态估计技术对系留磁性装置进行闭环控制的实验演示,以确定其对于机器人引导胶囊内窥镜检查的适用性。因此,通过采用这种姿态估计系统,可以进一步推动磁驱动胶囊内窥镜的闭环控制和智能自动化的进步,以实现临床实现。
更新日期:2018-06-25
down
wechat
bug