Development and evaluation of an MRI compatible finger rehabilitation device for stroke patients

This paper presents the design, development and magnetic resonance imagining (MRI) compatibility evaluation of a small size, compact and adjustable different finger phalange lengths rehabilitation device. This device employs ultrasonic motor as its actuator and adopts a novel six-link mechanism to drive the finger. The final system enables to provide two joints (the MCP and the PIP) in each finger to do flexion and extension motion with one degree of freedom (DOF). The MRI compatibility of the robot was also evaluated. The results demonstrate that there is neither an effect from the MRI environment on the robot performance, nor significant degradation on MRI images by the introduction of the robot in the MRI scanner. Finally, an fMRI study with subject was carried out, the result shows a stable brain activation was observed when the middle finger of the subject was driven to implement passive rehabilitation motion inside the MRI scanner.