Bioinspired robotic structures comprising soft actuation units have attracted increasing research interest. Taking advantage of its inherent compliance, soft robots can assure safe interaction with external environments, provided that precise and effective manipulation could be achieved. Endoscopy is a typical application. However, previous model-based control approaches often require simplified geometric assumptions on the soft manipulator, but which could be very inaccurate in the presence of unmodeled external interaction forces. In this study, we propose a generic control framework based on nonparametric and online, as well as local, training to learn the inverse model directly, without prior knowledge of the robot's structural parameters. Detailed experimental evaluation was conducted on a soft robot prototype with control redundancy, performing trajectory tracking in dynamically constrained environments. Advanced element formulation of finite element analysis is employed to initialize the control policy, hence eliminating the need for random exploration in the robot's workspace. The proposed control framework enabled a soft fluid-driven continuum robot to follow a 3D trajectory precisely, even under dynamic external disturbance. Such enhanced control accuracy and adaptability would facilitate effective endoscopic navigation in complex and changing environments.

Abstract-This article introduces a robotic manipulator to realize robot-assisted intra-cardiac catheterization in magnetic resonance imaging (MRI) environment. MRI can offer highresolution images to visualize soft tissue features such as scars or edema. We hypothesize that robotic catheterization, combined with the enhanced monitoring of lesions creation using MRI intraoperatively, will significantly improve the procedural safety, accuracy and effectiveness. This is designed particularly for cardiac electrophysiological (EP) intervention, which is an effective treatment of arrhythmia. We present the first MR Safe robot for intra-cardiac EP intervention. The robot actuation features small hysteresis, effective force transmission and quick response, which has been experimentally verified for its capability to precisely tele-manipulate a standard clinically used EP catheter. We also present timely techniques for real-time positional tracking in MRI and intra-operative image registration, which can be integrated with the presented manipulator to improve the performance of tele-operated robotic catheterization.Index Terms-MR Safe robot, robot-assisted intervention, MR image registration, positional tracking in MRI.

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