title: A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement.
abstract: Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0-10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation.
authors.affiliation: Automation and Interventional Medicine (AIM) Robotics Laboratory, Department of Mechanical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Weijian
authors.initials: W
authors.lastname: Shang
authors.affiliation: Automation and Interventional Medicine (AIM) Robotics Laboratory, Department of Mechanical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Su
authors.affiliation: Automation and Interventional Medicine (AIM) Robotics Laboratory, Department of Mechanical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Center for Holographic Studies and Laser micromechaTronics (CHSLT) and NanoEngineering, Science and Technology (NEST), Department of Mechanical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Cosme
authors.initials: C
authors.lastname: Furlong
authors.affiliation: Automation and Interventional Medicine (AIM) Robotics Laboratory, Department of Mechanical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Fischer
keywords: Fabry-Perot interferometer; MRI compatible; Needle insertion; Optical force sensor