Design and Performance Evaluation of a Force/Torque Sensor for Tele-Operated Catheterization Procedures

A tele-operated robotic catheterization system can significantly alleviate the surgeons from radiation exposure and fatigue resulted from long-standing time with protective suits. Proximal force/torque signals imply the critical information about the contact forces between the catheter and its surrounding structures. This paper presents a compact, cost-effective force and torque sensing device suitable for catheterization procedures to measure the proximal force/torque signals of the input catheter. The device consists of a rotatable and linear retractable mechanism, a laser mouse sensor, and a coil spring. As the stretched, compressed, and twisted values vary due to the sliding joint, the force and torque signals can be computed based on Hooke's law. The proposed sensing device has many advantages, such as cost-effective, easily miniaturized and customized, and can be extended to the magnetic resonance imaging compatible sensors. The experimental results with step response and time-varying loads by comparing to an ATI Nano17 force/torque sensor show that the root mean squared error for force and torque measurement is 0.042 N and 0.228 mNm, respectively.