MRI Compatibility
To be MRI compatible, a robot needs to safely operate and perform its functions within the magnetic field of the MRI without deteriorating the image quality. Thus, the development of MRI robots is a very challenging engineering task because MRI scanners use magnetic fields of very high density (3 teslas is now common), and most of the components commonly used in robotics may not be used in close proximity of the magnet.
Researchers have attempted to overcome the difficulties of robotic components in MRI in a variety of ways; some have placed controls and other magnetic sensitive units outside the shielded room of the MRI. These controls will be connected to the robot by either hydraulic or pneumatic transmission lines.
Aside from the difficulties of robotics use in the large magnetic fields found with MRI, the small gap between the MRI and the patient limits the physical size of robots used as the inner radius of an MRI is typically 55 cm.
In addition to the robot itself, there must be a way to track the position, orientation and force being applied to the instrument. Though this may potentially be done with continuous MRI, some uses of MRI robots may make continuous MRI undesirable due to potential interference between the MRI robot and the changing magnetic fields used in MRI. Many times this tracking is done using some sort of optical system which may include fiber optics.
Read more about this topic: MRI Robot