In the last decades, fiber Bragg gratings (FBGs) have become increasingly attractive to medical applications due to their unique properties such as small size, biocompatibility, immunity to electromagnetic interferences, high sensitivity and multiplexing capability. FBGs have been employed in the development of surgical tools, assistive devices, wearables, and biosensors, showing great potentialities for medical uses. This paper reviews the FBG-based measuring systems, their principle of work, and their applications in medicine and healthcare. Particular attention is given to sensing solutions for biomechanics, minimally invasive surgery, physiological monitoring, and medical biosensing. Strengths, weaknesses, open challenges, and future trends are also discussed to highlight how FBGs can meet the demands of nextgeneration medical devices and healthcare system.

The integration of fiber Bragg grating (FBG) sensors in lithium-ion cells for in-situ and in-operando temperature monitoring is presented herein. The measuring of internal and external temperature variations was performed through four FBG sensors during galvanostatic cycling at C-rates ranging from 1C to 8C. The FBG sensors were placed both outside and inside the cell, located in the center of the electrochemically active area and at the tab-electrode connection. The internal sensors recorded temperature variations of 4.0 ± 0.1 °C at 5C and 4.7 ± 0.1 °C at 8C at the center of the active area, and 3.9 ± 0.1 °C at 5C and 4.0 ± 0.1 °C at 8C at the tab-electrode connection, respectively. This study is intended to contribute to detection of a temperature gradient in real time inside a cell, which can determine possible damage in the battery performance when it operates under normal and abnormal operating conditions, as well as to demonstrate the technical feasibility of the integration of in-operando microsensors inside Li-ion cells.

Objective: Arterial stiffness, namely pulse wave velocity (PWV), is an emerging biomarker in the assessment of vascular health. This meta-analysis aims to determine the effects of exercise training on PWV in patients with hypertension, and to identify the possible moderator variables (e.g. type of exercise) of the effect of exercise on PWV. Methods: MEDLINE, EMBASE, Cochrane and Web of Science were searched up until July 2019 for randomized controlled trials assessing the effect of exercise interventions lasting 4 or more weeks on PWV in adults with hypertension. Random-effects modelling was used to compare changes from pre to postintervention in PWV between exercise and control groups. Data were reported as weighted mean difference (WMD) and 95% confidence interval (95% CI). Protocol registration: PROSPERO registration number CRD42019138658. Results: We included 14 trials (15 interventions), involving five aerobic, two dynamic resistance, six combined and two isometric resistance groups, totalling 642 participants with hypertension. PWV was significantly reduced by exercise training [(WMD (95% CI) = −0.76 m/s (−1.05 to −0.47)]. Analysis of moderator variables showed that aerobic exercise [WMD (95% CI) = −0.70 m/s (−1.20 to −0.19)], combined exercise [WMD (95% CI) = −0.74 m/s (−1.41 to −0.08)] and isometric resistance exercise [WMD (95% CI) = −0.98 m/s (−1.24 to −0.73)] reduced PWV. There was no significant reduction in PWV in participants undertaking dynamic resistance training [WMD (95% CI) = −0.58 (−1.58 to 0.42)] Conclusion: This meta-analysis supports that exercise interventions based on aerobic, combined or isometric exercise are suitable to improve PWV in adults with hypertension.