MrBot is a fully-actuated robot for image-guided access of the prostate gland. The robot is customized for transperineal needle insertion and designed to be compatible with Magnetic Resonance Imagers (MRI) of the highest field strength. MrBot can accommodate various needle drivers for different percutaneous interventions such as biopsy, thermal ablations, or brachytherapy.

For MRI compatibility the robot is exclusively constructed of nonmagnetic and dielectric materials such as plastics, ceramics, and rubbers and is electricity free. The system utilizes a new type of motor specifically designed for this application, the pneumatic step motor. This unique motor design provides easily controllable, precise, and safe pneumatic actuation. Light based encoding is used for feedback, so that all electric components are distally located outside the imager’s room.

Motion tests showed very fine performance with fraction of millimeter accuracy. Imager compatibility tests performed in scanners up to 7 Tesla showed outstanding MRI compatibility, independent of the field strength. MRI-guided needle targeting experiments showed that the tip of the needle may be placed within 1mm of a desired target selected in the image. Cadaver and animal tests are in progress. Partial results are very promising.