MR compatible manipulandum with ultrasonic motor for fMRI studies

MR compatible apparatus is essential to design new tasks for fMRI study. This paper described the development of an MR compatible manipulandum actuated by the ultrasonic motors, which was able to work within MRI scanner and to perform fMRI task continuously during finger movements. The prototype of manipulandum was able to produce two discriminable force fields: position dependent and velocity dependent force field. The control law was derived by the characteristic of velocity-phase difference-torque relationship of the ultrasonic motor. After MR compatibility was verified with signal noise ratio of the images, it was shown that the proposed prototype was able to use for fMRI study