Robotically Adjustable Magnetic Navigation System for Medical Magnetic Milli/Microrobots

Magnetic milli/microrobots and magnetic navigation systems have been widely investigated for medical applications due to their advantages of generating torque and force remotely and the simple mechanical structure of magnetic robots. However, there are very few cases that have been commercialized because of the limitations of conventional magnetic navigation systems (e.g., heavy weight, bulky structures, and limited compatibility with other medical devices). In this article, we propose a novel concept of a robotically adjustable magnetic navigation (RAMAN) system, which can adjust the size and position of its workspace using a robotic stage. We developed the concept and structure of the system to overcome the conventional limitations and then developed an optimization method to maximize the magnetic performance of the system. Several experiments were conducted to evaluate the performance of the RAMAN system and verify the control methods. According to the results, the RAMAN system, weight of just 910 kg, can generate a magnetic field within its workspace from 13.5 to 120 mT and adjust the height of the workspace from 200 to 400 mm. Finally, the effectiveness of the system was validated by manipulating the tethered magnetic robot in a planar open space and an artificial vascular environment.