FBG Sensors Monitoring Force and Deformation of the Traction Instrument in Pelvic Fracture Reduction Surgery

In robot-assisted pelvic fracture reduction surgery, precise control of the traction needle is essential for successful traction of the fractured bone to align with the anastomotic position. However, needle deformation during the procedure can compromise the navigation system’s accuracy, potentially causing over-traction, damage to adjacent tissues, and surgical failure. To address this issue, we propose a novel force sensing system that integrates fiber Bragg grating (FBG) sensors onto the traction needle, providing reliable mechanical feedback. The applied force on the needle is transduced through the wavelength shift of the FBGs, enabling the calculation of needle tip deformation using a mapping model correlating needle position offset and applied force. Experimental evaluation reveals the sensor’s high sensitivity in measuring lateral force (31.04 and 21.91 pm/N in the
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and
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directions, respectively) and commendable tracking accuracy for both force and deformation (with errors of 3.74%FS full scale (FS) and 1.280 mm). The proposed sensing system’s efficacy is further demonstrated through robot-assisted pelvic reduction surgery on an artificial pelvis, confirming the sensor’s capability to accurately measure traction force and instrument deformation during the procedure.