An MRI robot is a medical robot capable of operating within a Magnetic Resonance Imaging MRI scanner for the purpose of performing or assisting in image-guided interventions (IGI).
IGI interventions are commonly performed manually by physicians operating instruments such as needle based on medical images, in most medical field and in the Interventional_radiology specialty. IGI robots help manipulating the instrument or provide guidance for image-navigation. These have the potential to improve the performance of IGI because, unlike humans, robots are digital devices that may directly communicate with the digital imagers.
To be MRI compatible a robot needs to safely operate and perform its function within the magnetic field of the MRI without deteriorating the image quality. But the development of MRI robots is a very challenging engineering task, because MRI scanners use magnetic fields of very high density (3 Tesla is now common), and most of the components commonly used in robotics may not be used in close proximity of the magnet ( see Google video on MRI Safety]).
The URobotics research group at the Johns Hopkins University has developed an electricity-free, non-magnetic, and dielectric robot, MrBot. This operates with air for the motors and light for its sensors ( YouTube movie). This achievement was possible through the invention of a new type of pneumatic motor, the PneuStep, which allows for simple, fail-safe precision controlled motion.