Intravascular Ultrasound Robot Based on a Permanent Magnet System: Magnetic-Actuated Imaging and Magnetic Localization Navigation

For interventional imaging devices, the magneticactuated approach holds great promise in enhancing catheter flexibility and improving imaging performance in complex environments, as exemplified in intravascular ultrasound (IVUS) and optical coherence tomography (OCT) systems. However, obtaining real-time pose estimation of the magnetic robot and compensating for non-uniform rotational distortion (NURD) in imaging remain critical challenges for clinical applications. This study proposes a solution to the aforementioned issues based on a miniaturized embedded magnetic field sensing module, which measures the resultant magnetic field from both the driving and the response magnets, and demonstrates the navigation mode of the magnetic-actuated IVUS (MIVUS) robot in a vascular model. In a permanent magnet space manipulated by the robotic arm, the position tracking error of the prototype robot is 3.34 ± 1.74 mm, and the orientation error is 1.78 ± 1.15°. Furthermore, through front-end encoding, high-fidelity ultrasound (US) images with substantially suppressed NURD were reconstructed in tissue-mimicking phantoms. This study presents a synergistic magnetic navigation and imaging concept and provides preliminary validation.