This paper presents a closed-loop magnetic manipulation framework for robotic transesophageal echocardiography (TEE) acquisitions. Different from previous work on intracorporeal robotic ultrasound acquisitions that focus on continuum robot control, we first investigate the use of magnetic control methods for more direct, intuitive, and accurate manipulation of the distal tip of the probe. We modify a standard TEE probe by attaching a permanent magnet and an inertial measurement unit sensor to the probe tip and replacing the flexible gastroscope with a soft tether containing only wires for transmitting ultrasound signals, and show that 6-DOF localization and 5-DOF closed-loop control of the probe can be achieved with an external permanent magnet based on the fusion of internal inertial measurement and external magnetic field sensing data. The proposed method does not require complex structures or motions of the actuator and the probe compared with existing magnetic manipulation methods. We have conducted extensive experiments to validate the effectiveness of the framework in terms of localization accuracy, update rate, workspace size, and tracking accuracy. In addition, our results obtained on a realistic cardiac tissue-mimicking phantom show that the proposed framework is applicable in real conditions and can generally meet the requirements for tele-operated TEE acquisitions.

翻译：本文提出了一种用于机器人经食管超声心动图（TEE）采集的闭环磁操控框架。与以往聚焦于连续体机器人控制的体内机器人超声采集工作不同，我们首次探索利用磁控制方法对探头远端尖端进行更直接、直观且精确的操控。通过将永磁体和惯性测量单元传感器附着于标准TEE探头尖端，并将柔性胃镜替换为仅含传输超声信号导线的软缆线，我们展示了基于内部惯性测量与外部磁场传感数据融合，可利用外部永磁体实现探头的6自由度定位与5自由度闭环控制。与现有磁操控方法相比，所提方法无需执行器或探头的复杂结构或运动。我们开展了大量实验，从定位精度、更新速率、工作空间及跟踪精度等方面验证了该框架的有效性。此外，在逼真心肌仿生体模上获得的结果表明，该框架适用于真实条件且可基本满足远程操控TEE采集的需求。