Three-Dimensional Controlled Motion of a Microrobot using Magnetic Gradients

This paper presents the endovascular navigation of a ferromagnetic microdevice using magnetic resonance imaging (MRI)-based predictive control. The concept was studied for the future development of microrobots designed to perform minimally invasive interventions in remote sites accessible through the human cardiovascular system. A system software architecture is presented illustrating the different software modules to allow three-dimensional (3-D) navigation of a microdevice in blood vessels, namely: (i) vessel path extraction, (ii) magnetic gradient steering, (iii) tracking and (iv) closed-loop navigation control. First, the navigation path of the microrobot into the blood vessel is extracted using the Fast Marching Method from the pre-operation images (3-D MRI imaging) to guide the microrobot from the injection point to the tumor area through the anarchic vessel network. Based on the pre-computed path, a Model Predictive Controller is proposed for robust time-multiplexed navigation along a 3-D path in the presence of pulsative flow. The simulation results suggest the validation of the proposed image processing and control algorithms. © Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2011