Abstract
Fibre Bragg Grating (FBG) sensors are gaining popularity in biomedical engineering. However, specific standards for in vivo testing for their use are absolutely limited. In this study, in vitro experimental tests were performed to investigate the behaviors and applications of gratings attached to intact and fractured thighbone for a range of compression loading (<300 N) based around some usual daily activities. The wavelength shifts and the corresponding strain sensitivities of the FBG sensors were measured to determine their effectiveness in monitoring the femoral fracture healing process. Four different arrangements of FBG sensors were selected to measure strains at different critical locations on the femoral sawbones surface. Data obtained for intact and plated sawbones were compared using both embedded longitudinal and coiled FBG arrays. Strains were measured close to the fracture, posterior linea aspera and popliteal surface areas, as well as at the proximal and distal ends of the synthetic femur; their responses are discussed herein. The gratings on the longitudinally secured FBG arrays were found to provide high levels of sensitivity and precise measurements, even for relatively small loads (<100 N). Nevertheless, embedding angled FBG sensors is essential to measure the strain generated by applied torque on the femur bone. The maximum recorded strain of the plated femur was 503.97 µε for longitudinal and −274.97 µε for coiled FBG arrays, respectively. These project results are important to configure effective arrangements and orientations of FBG sensors with respect to fracture position and fixation implant for future in vivo experiments.
Highlights
Femoral fracture is a life-threatening injury, usually caused by high energy impact and associated with major local soft-tissue injury, as well as other more serious axial damage [1,2,3,4,5,6,7]
The use of Fibre Bragg Grating (FBG) sensors to monitor bone strain under applied load is investigated as a potential method to assess the strength of the bone at various stages after surgery in order to determine an optimal point at which patients can resume load-bearing activities
This study investigates effective arrangements for the FBG sensors arrays and examines practical sensors orientations for future in vivo applications
Summary
Femoral fracture is a life-threatening injury, usually caused by high energy impact and associated with major local soft-tissue injury, as well as other more serious axial damage [1,2,3,4,5,6,7]. Gauges and sensor types are utilized to measure strain and stiffness in bone and orthopaedic implants [22,23] These sensors include conventional resistive strain gauges, as well as those that employ optical fibres with Fibre Bragg Gratings (FBGs). In vitro studies were performed on implants in order to understand their role on bone fracture fixation, and to evaluate their designs for in vivo investigations to monitor strains under various loading conditions [24]. Application of strain analysis sensors throughout the bone fracture recovery assessment process is uncommon and mostly limited to conventional resistive strain gauges. The applications of FBG sensors are investigated with focus on the sensitivity and simplicity of installment and the response, interrogation and implementation of in vitro bone-implant strain analysis on composite synthetic fractured femur. This study investigates effective arrangements for the FBG sensors arrays and examines practical sensors orientations for future in vivo applications
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
