Force sensing of multiple-DOF cable-driven instruments for minimally invasive robotic surgery

Abstract

BACKGROUND: Force sensing for robotic surgery is limited by the size of the instrument, friction and sterilization requirements. This paper presents a force-sensing instrument to avoid these restrictions. METHODS: Operating forces were calculated according to cable tension. Mathematical models of the force-sensing system were established. A force-sensing instrument was designed and fabricated. A signal collection and processing system was constructed. RESULTS: The presented approach can avoid the constraints of space limits, sterilization requirements and friction introduced by the transmission parts behind the instrument wrist. Test results showed that the developed instrument has a 0.03 N signal noise, a 0.05 N drift, a 0.04 N resolution and a maximum error of 0.4 N. The validation experiment indicated that the operating and grasping forces can be effectively sensed. CONCLUSIONS: The developed force-sensing system can be used in minimally invasive robotic surgery to construct a force-feedback system.