FBG-Based Sensorized Surgical Instrument for Force Measurement in Minimally Invasive Robotic Surgery

To address the lack of force measurement in minimally invasive robotic surgery, this article develops the sensorized surgical instrument based on fiber Bragg grating (FBG) technology. The sensorized surgical instrument detects forces in two directions by affixing three FBGs at 120° intervals on the shaft of the surgical instrument. For the designed sensorized surgical instrument, first, finite-element simulation is used to explore the impact of the trocar on the strain at the adhesive points of FBGs in the operation state. Subsequently, the study theoretically analyzes how the fixed position of the instrument on the calibration platform affects the strain. Furthermore, finite-element simulation is used to compare strain differences between the calibration state and the operation state. Finally, the static calibration experiment establishes the decoupling matrix for the instrument and demonstrates that changing its fixed position on the calibration platform yields a maximum force measurement error of 0.92%. Additionally, the accuracy of sensorized surgical instrument force measurement is demonstrated by hanging a weight from the end of the instrument and its surgical efficacy is proven in tumor localization tasks.