This dissertation addresses topics related to developing interventional assistant devices
for Magnetic Resonance Imaging (MRI). MRI can provide high-quality 3D visualization
of target anatomy and surrounding tissue, but the benefits can not be readily harnessed for
interventional procedures due to difficulties associated with the use of high-field (1.5T or
greater) MRI. Discussed are potential solutions to the inability to use conventional mecha-
tronics and the confined physical space in the scanner bore.
This work describes the development of two apparently dissimilar systems that repre-
sent different approaches to the same surgical problem - coupling information and action
to perform percutaneous (through the skin) needle placement with MR imaging. The first
system addressed takes MR images and projects them along with a surgical plan directly
on the interventional site, thus providing in-situ imaging. With anatomical images and a
corresponding plan visible in the appropriate pose, the clinician can use this information to
perform the surgical action.
My primary research effort has focused on a robotic assistant system that overcomes
the difficulties inherent to MR-guided procedures, and promises safe and reliable intra-prostatic needle placement inside closed high-field MRI scanners. The robot is a servo
pneumatically operated automatic needle guide, and effectively guides needles under real-
time MR imaging. This thesis describes development of the robotic system including
requirements, workspace analysis, mechanism design and optimization, and evaluation of
MR compatibility. Further, a generally applicable MR-compatible robot controller is de-
veloped, the pneumatic control system is implemented and evaluated, and the system is
deployed in pre-clinical trials. The dissertation concludes with future work and lessons
learned from this endeavor
