Real-time Software Platform Design for In-Vivo Navigation of a Small Ferromagnetic Device in a Swine Carotid Artery Using a Magnetic Resonance Imaging System

Using an 1.5 T Siemens clinical magnetic resonance imaging system (MRI), a 1.5 mm diameter ferromagnetic bead is moved across a pre-planned path in the carotid artery of a 25 kg living swine. The software architecture for the navigation and path planning is herein described. Using the real-time feedback capabilities of recent MRIs, the device is moved, controlled and tracked using the magnetic gradients coils already present for imaging purposes. Navigation of the ferromagnetic device has been achieved with a peak velocity of about 13 cm/s through a set of pre established 11 waypoints. The dedicated software architecture presented in this paper lies in a modified real-time MRI imaging sequence. The dedicated architecture permits the navigation of the ferromagnetic bead with an operating frequency of 24 Hz real-time control of the magnetic core is achieved through the implementation of a simple 2D PID controller incorporated in the presented software platform.