Estimating External Force along FBG-integrated Flexible Instruments by Using Cosserat Rod Theory

A method combining the Cosserat rod theory with fiber Bragg grating (FBG) sensors is proposed to estimate single load along the length of a Nitinol rod, specifically a flexible instrument for medical applications. The internal stress transmission model within the flexible instrument under external forces is simulated and validated experimentally. Results show that the mean estimation error for the unidirectional force magnitude is 7.8%.