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.