A novel 4‐DOF surgical instrument with modular joints and 6‐Axis Force sensing capability

Background It is difficult for surgeons to exert appropriate forces during delicate operations due to lack of force feedback in robot‐assisted minimally invasive surgery (RMIS). A 4‐DOF surgical grasper with a modular wrist and 6‐axis force sensing capability is developed. Methods A grasper integrated with a miniature force and torque sensor based on the Stewart platform is designed, and a cable tension decomposition mechanism is designed to alleviate influence of the cable tension to the sensor. A modularized wrist consisting of four joint units is designed to facilitate integration of the sensor and eliminate coupled motion of the wrist. Results Sensing ranges of this instrument are ±10 N and ±160 N mm, and resolutions are 1.2% in radial directions, 5% in axial direction, and 4.2% in rotational directions. An ex vivo experiment shows that this instrument prototype successfully measures the interaction forces. Conclusions A 4‐DOF surgical instrument with modular joints and 6‐axis force sensing capability is developed. This instrument can be used for force feedback in RMIS. Copyright © 2016 John Wiley & Sons, Ltd.