Single Optical Fiber with Dual FBG Sensors: Simplifying 2-DOF Force Sensing in Minimally Invasive Surgery

This study introduces a novel 2-DOF force sensing technique utilizing Fiber Bragg Grating (FBG) sensors, designed for constrained environment in minimally invasive surgeries (MIS). Addressing the limitations of traditional designs that require multiple fibers to measure axial force, lateral force, and temperature, this innovative approach uses a single optical fiber with two FBG sensors. By leveraging structural asymmetry and coating variations, the device achieves high sensitivity and decoupled measurements of these parameters, simplifying complexity and enhancing efficiency. Simulation results validate the design, showing independent detection of temperature with a resolution of 0.025°C and force components with < 1 gF in axial and < 0.1 gF in lateral directions. This advancement promises to improve precision, safety, and efficacy in medical procedures, particularly under constraints of space and resources.