Motion Generation in MRI Using an Electrostatic Linear Motor for Visualizing Internal Deformation of Soft Objects by tagged cine-MRI

This paper introduces a new actuating system for MRI study, combining the linear electrostatic film motor and tagged cine-MRI process to visualize internal deformation of soft objects. The linear electrostatic film motor is MR-compatible, simple structure, and easily controlled by open-loop. Motion of the motor and MR scanning are synchronized by a trigger and the motor conducts more than 250 cycles of reciprocating movements to create deformation in the soft subjects. A force sensor is developed using shielded strain gauges to monitor the applied force to the objects during MR scanning and the MR-compatibility of the newly made sensor was evaluated. The developed system was tested against gel samples. The obtained images using the system clearly showed the internal deformation of the soft samples under pushing force given by the electrostatic motor. Although further modifications are desirable, the pushing force was successfully measured by the newly made force sensor during MR scanning.