A Stiffness-Changing Continuum Robotic Manipulator for Possible Use in MRI-Guided Neurosurgical Interventions

Surgical robotics have helped surgeons for more than two decades using sophisticated and operation-based devices. Different kinds of surgical robots have been developed for specific purposes. In recent times, stiffness changing robots are in the spotlight due to their necessity. The interaction force on neighboring tissues during navigation to surgical target can be reduced owing to the low stiffness and the stiffness can be increased to provide high payloads as it reaches the surgical site. In this work, a 2-DOF soft robot with stiffness changing capability is presented for tumor removal in neurosurgery under MRI-guidance. A floating fixed-point approach is used that changes the physical length of the manipulator to decrease deflection and increase stiffness. Experimental results confirmed that the stiffness could be varied more than three and a half times than the initial value. The robot can bend 37.46° in right and left and 38.56° in up and down direction. The current version of the robot is joystick-operated and can be controlled manually. Finally, the manipulator is composed of MR-compatible materials allowing it to be used in MR-guided interventions.