Development of a Gripper with Variable Stiffness for a CT-Guided Needle Insertion Robot

In recent years, interventional radiology (IR) as a medical procedure has attracted considerable attention. Among the various IR techniques, computed tomography (CT)-guided IR is performed by inserting a specific needle into a lesion under CT guidance, leading to this medical procedure being less invasive. However, as the procedure requires the doctor to be positioned near the CT, radiation exposure may be a major concern. To overcome this problem, we developed a remote-controlled robotic system for needle insertion during CT-guided interventional procedures. The current needle holder for the robot is risky in that it might hurt a patient since a needle is always held firmly even when the patient moves. To solve this problem, we designed and fabricated a gripper with variable stiffness through jamming transition. Subsequently, we conducted experiments to investigate the effect of elements constituting the gripper to improve its performance.