3-D Force Sensing Strategy of Laryngeal Continuum Surgical Robot Based on Fiber Bragg Gratings

The laryngeal tissue is sensitive to the operating force of the surgical instrument in the tissue resection. A large operating force may cause rupture of the vocal cords and surrounding tissues, which affect the patients' normal voice. However, a small operating force cannot achieve tissue resection. Based on experience, surgeons can estimate the operating force in the process of using a surgical robot. The estimated operating force is usually inaccurate, which may increase the failure rate of surgery. Therefore, a fiber Bragg gratings (FBGs)-based 3-D force sensing sensor for the surgical robot, which consists of two flexible hinges in series is designed. And the force sensing model is constructed through mechanical modeling and temperature decoupling algorithm. The experimental results show that the designed sensor has a resolution of 14.3, 9.7, and 13.8 mN for external forces F-x, F-y, and F-z, respectively. The proposed mechanism has good axial and lateral force sensing capability. In the experiment of simulating diseased tissue with the silicone-steel ball, the designed sensor can accurately determine the position of the steel ball, which verifies the effectiveness and feasibility of the designed FBG sensor in force perception.