A New Transmission Mechanism for the Actuation of Manipulators for Magnetic Resonance Imaging (MRI) Guided Interventions

Abstract

This work presents a novel mechanism for force transmission specially designed for actuating robotic manipulators inside the MR scanner in order to perform interventions with real-time MRI guidance. This force transmission mechanism, herein referred to as Solid Media Transmission (SMT), uses channels filled with solid media and force is transmitted from one to the other end by the translation of the media inside the respective tubing. SMT lines were implemented with material compatible and safe to the MR environment. Bench top studies on a 2-m long SMT line, using specially designed sensor units to measure force and displacement, demonstrated that SMT gave out immediate motion response and over 80% displacement transfer efficiency. It indicates the feasibility to use SMT for manipulator tool positioning. In the MRI studies of the SMT mechanism we used a conventional stepper motor as a cost-efficient and simple powering source option. To ensure MR compatibility and safety at a 1.5 Tesla scanner we used a 4-m long SMT to place the motor outside of the 5 Gauss line, and to reduce electromagnetic interference from the controllers we used shielding and filtering of the drive signals. Force was successfully transmitted over the 4-m SMT with an efficiency of over 50%. Moreover, the custom shielding and filtering resulted to minimal EMI noise of less than 6% of the phantom signal.

The original version of this chapter was inadvertently published with an incorrect chapter pagination 673–678 and DOI 10.1007/978-3-319-32703-7_130. The page range and the DOI has been re-assigned. The correct page range is 679–684 and the DOI is 10.1007/978-3-319-32703-7_131. The erratum to this chapter is available at DOI: 10.1007/978-3-319-32703-7_260

An erratum to this chapter can be found at http://dx.doi.org/10.1007/978-3-319-32703-7_260