Fiber Bragg grating-based temperature-compensated force sensor development for minimally invasive surgery

Abstract

A Fiber Bragg Grating (FBG) based force sensor with high-sensitivity and temperature compensation capability. It can be used to accurately measure the contact force (CF) between medical equipment and tissues or organs in minimally invasive surgery (MIS). To achieve temperature compensation, a novel design incorporating dual elastomer-based dual FBGs is employed, and its effectiveness is verified through finite element simulation. After temperature compensation, the developed sensor has a sensitivity of 54 pm/N, a resolution of 0.019 N, and a root-mean-square error (RMSE) of 0.064 N. The utilization of temperature disturbances for measuring distal contact force demonstrates a substantial enhancement compared to direct measurement methods. Additionally, in vitro experiments are conducted using a silicone vascular model, demonstrating the sensor's capability to detect certain alterations in vascular pathways. Finally, a simulated palpation liver experiment confirmed that the designed force sensor can preliminary detect of the relative hardness of the tissue based on the magnitude of the CF. In vitro experiments have proved that the designed FBG force sensor has a practical value in MIS.