Abstract
Background. Stress at work has been broadly acknowledged as a worldwide problem and has been the focus of concern for many researchers. Firefighting, in particular, is frequently reported as a highly stressful occupation. In order to investigate firefighters' occupational health in terms of stress events, perceptions, symptoms, and physiological reactions under real-world conditions, an ambulatory assessment protocol was developed. Methods. Seventeen firefighters' cardiac signal was continuously monitored during an average of three shifts within a working week with medical clinically certified equipment (VitalJacket (R)), which allows for continuous electrocardiogram (ECG) and actigraphy measurement. Psychological data were collected with a software application running on smartphones, collecting potential stressful events, stress symptoms, and stress appraisal. Results. A total of 450.56 h of medical-quality ECG were collected, and heart rate variability (HRV) analysis was performed. Findings suggest that although 'fire' situations are more common, 'accidents' are more stressful. Additionally, firefighters showed high levels of physiological stress (based on AVNN and LF/HF HRV metrics) when compared to normative healthy population values that may not be diagnosed using merely self-reports. Discussion. The proposed ambulatory study seems to be useful for the monitoring of stress levels and its potential impact on health of first responders. Additionally, it could also be an important tool for the design and implementation of efficient interventions and informed management resolutions in real time. Potential applications of this research include the development of quantified occupational health (qOHealth) devices for real life monitoring of emergency personnel stress reactions.

Abstract
Background: Stress is a complex process with an impact on health and performance. The use of wearable sensor-based monitoring systems offers interesting opportunities for advanced health care solutions for stress analysis. Considering the stressful nature of firefighting and its importance for the community’s safety, this study was conducted for firefighters. Objectives: A biomonitoring platform was designed, integrating different biomedical systems to enable the acquisition of real time Electrocardiogram (ECG), computation of linear Heart Rate Variability (HRV) features and collection of perceived stress levels. This platform was tested using an experimental protocol, designed to understand the effect of stress on firefighter’s cognitive performance, and whether this effect is related to the autonomic response to stress. Method: The Trier Social Stress Test (TSST) was used as a testing platform along with a 2-Choice Reaction Time Task. Linear HRV features from the participants were acquired using an wearable ECG. Self-reports were used to assess perceived stress levels. Results: The TSST produced significant changes in some HRV parameters (AVNN, SDNN and LF/HF) and subjective measures of stress, which recovered after the stress task. Although these short-term changes in HRV showed a tendency to normalize, an impairment on cognitive performance was found after performing the stress event. Conclusion: Current findings suggested that stress compromised cognitive performance and caused a measurable change in autonomic balance. Our wearable biomonitoring platform proved to be a useful tool for stress assessment and quantification. Future studies will implement this biomonitoring platform for the analysis of stress in ecological settings. © 2018 Rodrigues et al.

Abstract
Current mobile revolution is leading to an increase of wearable health devices development and consequently a growth in ambulatory monitoring area. These systems can be applied in ambulatory diseases management and diagnosis, personal health monitoring or sports performance enhancement, providing physiological and body-Area ambiance data during daily normal activities. Nowadays several devices in the market have this type of technology, being one of them the VitalJacket® (VJ®), a product from Biodevices, S.A. This device is a medical certified smart t-shirt with textile embedded electronics for ambulatory monitoring of electrocardiogram (ECG), Heart Rate (HR) and Accelerometer (Acc) data that is in the market since 2008. © 2017 IEEE.

Abstract
Under the VitalResponder® (VR) line of research, mostly funded by the Carnegie Mellon University (CMU)-Portugal program, we have been developing, in partnership with colleagues from CMU, novel wearable monitoring solutions for hazardous professionals such as first responders (FR). We are exploring the synergy between innovative wearable technologies, scattered sensor network and precise localization to provide secure, reliable and effective first-response information services in emergency scenarios. This enables a thorough teams’management, namely on FR exposure to different hazardous elements, effort levels and critical situations that contribute to team members’ stress and fatigue levels. © The Institution of Engineering and Technology 2017.

Abstract
Abstract Background Seizures commonly affect the heart rate and its variability. The increased interest in this area of research is related to the possible connection with sudden unexpected death in epilepsy (SUDEP). Generalized tonic-clonic seizures (GTCS) are reported as the most consistent risk factor for SUDEP. However, the general risk of seizures (and their type) on cardiac function still remains uncertain. Purpose To evaluate the influence of seizure type (GTCS vs non-GTCS) on ictal and early post-ictal Heart Rate Variability (HRV) in patients with refractory epilepsy. Methods From January 2015 to July 2018, we prospectively evaluated 121 patients admitted to our institution's Epilepsy Monitoring Unit with focal resistant epilepsy. All patients underwent a 48-hour Holter recording. We included only patients who had both GTCS and non-GTCS during the recording and selected the first seizure of each type to analyze. HRV (AVNN, SDNN, RMSSD, pNN50, and LF/HF) was evaluated by analyzing 5-min-ECG epochs, starting with the seizure onset (ictal and early post-ictal period). The study was approved by our Institution Ethics Committee and all patients gave informed consent. Results Fourteen patients were included (7 Females, 4 patients with Temporal Lobe Epilepsy). The median age was 39 years (min-max, 18–57). Thirty-six percent presented cardiovascular risk factors without known cardiac disease. A significant statistical reduction was found for AVNN (p=0.013), RMSSD (p=0.008), pNN50 (p=0.005) and HF (p=0.003), during GTCS when compared with non-GTCS (Wilcoxon test, p<0.05; two tailed). Conclusion Our study shows a significant reduced vagal tone during GTCS when compared with non-GTCS. Hence, GTCS had a more pronounced impact on HRV changes than other seizure types, which can be associated with higher SUDEP risk after GTCS.

Abstract
Abstract Background Heart Rate Variability (HRV) is an increasing area of interest in patients with epilepsy. The effects of epilepsy on the autonomic control of the heart are not completely understood and that autonomic dysfunction has been implicated in some cases of Sudden Unexpected Death in Epilepsy (SUDEP). Objective To study the influence of generalized tonic-clonic seizures (GTCS) on HRV of patients with focal refractory epilepsy. Method We prospectively evaluated (January 2015 to July 2018) 121 patients admitted to our institution's Epilepsy Monitoring Unit. All patients performed a 48-hour Holter recording. Patients who had GTCS during the recording were included and we selected the first GTCS as the index seizure. HRV (AVNN, SDNN, RMSSD, pNN50, and LF/HF) was evaluated by analyzing 5-min-ECG epochs during inter-ictal and post-ictal periods: baseline, pre-ictal (5 min before the GTCS seizure), post-ictal (5 min after the seizure), and late post-ictal (>5 hours after the seizure). We compared HRV data from these patients with normative values for a healthy population (controlling age and gender). The study was approved by our Institution Ethics Committee and all patients gave informed consent. Results Twenty three patients were included (mean age: 38.61±11.58; 70% Female). Thirty percent presented cardiovascular risk factors without known cardiac disease. We found significant differences between the analyzed periods for all but one (LF/HF) HRV metrics (using Friedman test, p<0.05, two-tailed). Specifically during the post-ictal period, we found a significant reduction for AVNN, SDNN, RMSSD and pNN50 (Wilcoxon test, p<0.05; two-tailed). LF/HF was increased during this period, but changes were not statistically significant. There was also a tendency for a reduction of AVNN, SDNN, RMSSD and pNN50 and an increase of LF/HF in our patients during all the analyzed periods when compared to normative healthy population values. Conclusion Our work shows reduced HRV after a GTCS in patients with focal resistant epilepsy, both in inter-ictal and post-ictal periods, when compared to normative healthy population values. These results might reflect long term structural changes in autonomic centers. The HRV changes were significant particularly during the post-ictal period, and should prompt further investigation, giving this period is critical for SUDEP.