“…However, Fiber Bragg Grating (FBG) has been more frequently used to monitor pulses in recent years, considering its unique advantages, e.g., its high sensitivity, immunity to electromagnetic interference, light weight, skin-friendly properties, low cost, and high flexibility. By now, FBG has been used to measure pulses noninvasively for different applications based on pulse waveform feature analysis [37][38][39], for example in cardiorespiratory [40], blood pressure [41], and arterial compliance [42]. So far, there has been only one study, published in 2015, that measured the carotid-radial PTT [43] using FBG for the analysis of systolic blood pressure.…”