Design of a 6 DoF Parallel Robot for MRI-guided Interventions

Abstract

In this work, the design, analysis, and characterization of a 6 DoF parallel robot for MRI guided applications is presented. The primary motivation for developing this robot is to create a general purpose robotic platform capable of producing accurate 6 DoF motion inside the MRI bore to perform needle-based interventional procedures (i.e., radio-frequency ablation, biopsy) or generate accurate motion for other MRI-based experiments (i.e., motion compensation imaging sequence development, HIFU probe manipulation). The robot is driven by 6 pneumatic cylinder actuators and controlled via a robust sliding mode controller. Pneumatic actuator tracking experiments indicate that the system is able to achieve an average error of 0.69 ± 0.14 mm and 0.67 ± 0.40 mm for step signal tracking and sinusoidal signal tracking respectively. To demonstrate the feasibility of the parallel robot for needle insertion interventions, a tissue-mimic phantom experiment was performed in the benchtop environment, which indicated an average position error of 1.20 0.43 mm and an average orientation error of 1.09 0.57°, respectively.