A Three-Dimensional Catheter Distal Force Sensor Based on Fiber Bragg Grating for Cardiac Ablation

This paper presents a three-dimensional force sensor based on fiber Bragg grating (FBG) with small size and high accuracy, which is proposed to be used in cardiac ablation procedures to achieve high-precision force feedback when the catheter tip contacts the tissue. The sensor consists of two hybrid elastomers for monitoring transverse and axial forces, as well as appropriately enhancing the deformation generated in the three directions to improve the sensitivity of the sensor. The structural body is configured with five suspended optical fibers, which are fixed with glue at both ends, and a preload is applied to ensure that the optical fibers are in a suspended state to avoid the chirp phenomenon. The article derives the theoretical deformation generated when the structural body is stressed, and proposes a decoupling method between the stressed temperature and deformation of the FBG fiber. In order to support further correction and improvement of the structural body performance and to further validate the feasibility of the structure, simulations based on finite element modeling were performed. The structure is configured to separate forces in three directions so that their measurements do not interfere with each other, thus maximizing decoupling between force components for highly accurate and high-resolution results.