Fiber Bragg Gratings in Healthcare Applications: A Review

Fiber Bragg grating FBG is a periodic refractive change induced inside the fiber's core due to exposure to optical radiation. Being miniature, EMI (electromagnetic interference) resistant, and sensitive to physical conditions, such as temperature, strain, and relative humidity; FBGs have gained huge attention and their implementation can be witnessed in many domains varying from oil and mining to medicine and healthcare application. This paper presents an overview regarding the application of FBGs as potential sensors in monitoring various vital physiological signals and activities such as body temperature, heart rate, cardiorespiratory analysis and more. Intricate and delicate observations such as pressure and strain mapping in prosthetics, bone health monitoring, and measuring small-scale forces in medical instruments such as spinal needles have also been discussed in detail. Various methodologies and topologies of implementing FBGs for processing and analyzing physiological signals have also been presented. To provide a better and suitable insight into tracking the progress regarding the implementation of FBGs in medicine and healthcare, thematic research in chronological order for the past decade is presented in this work. An elaborate discussion stating various issues and problems such as determination of an appropriate index for plantar pressure monitoring, cross-sensitivity of FBGs, choice of polymer sheaths, the dependence of gait analysis on the type of foot and size, etc., have also been addressed. At last, in the wake of evaluating past works and future clinical applications, a conclusory remark paving a pathway for future possibilities and applications is additionally presented in this paper.