An Automatic Magnetically Robotic System Using a Double-Loop Stable Control Method for Guidewire Steering

Magnetically steerable endovascular guidewire robotic systems that are capable of automatic agile navigation have great potential for medical applications, such as endovascular interventional surgery. In addition, the guidewire robotic systems save doctors from radiation exposure. Some magnetic endovascular guidewires have been designed by researchers. However, they are primarily open-loop controlled. This article aims to investigate methods of closed-loop control of a magnetic endovascular guidewire. First, a new fully automatic magnetic guidewire steering system is developed, including a flexible industrial robot arm, and then, the guidewire steering problem is formulated and modeled with physical and mathematical analysis. Second, a double-loop magnetic control strategy, including the velocity (outer controller) and direction controllers (inner controller), is proposed using the exponential sliding mode control method. Meanwhile, the system stability is analyzed based on the Lyapunov theory and the stable controller parameter constraints are obtained. Simulation examples verify that the proposed controller has no overshot problem, which can significantly avoid vessel damage. Finally, the experimental examples demonstrate the effectiveness of our proposed method, which has significant value for practical surgical applications in near future.