{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T14:57:26Z","timestamp":1780498646166,"version":"3.54.1"},"reference-count":96,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,5,16]],"date-time":"2020-05-16T00:00:00Z","timestamp":1589587200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Chronic stress is the main cause of health problems in high-risk jobs. Wearable sensors can become an ecologically valid method of stress level assessment in real-life applications. We sought to determine a non-invasive technique for objective stress monitoring. Data were collected from firefighters during 24-h shifts using sensor belts equipped with a dry-lead electrocardiograph (ECG) and a three-axial accelerometer. Levels of stress experienced during fire incidents were evaluated via a brief self-assessment questionnaire. Types of physical activity were distinguished basing on accelerometer readings, and heart rate variability (HRV) time series were segmented accordingly into corresponding fragments. Those segments were classified as stress\/no-stress conditions. Receiver Operating Characteristic (ROC) analysis showed true positive classification as stress condition for 15% of incidents (while maintaining almost zero False Positive Rate), which parallels the amount of truly stressful incidents reported in the questionnaires. These results show a firm correspondence between the perceived stress level and physiological data. Psychophysiological measurements are reliable indicators of stress even in ecological settings and appear promising for chronic stress monitoring in high-risk jobs, such as firefighting.<\/jats:p>","DOI":"10.3390\/s20102834","type":"journal-article","created":{"date-parts":[[2020,5,18]],"date-time":"2020-05-18T02:43:42Z","timestamp":1589769822000},"page":"2834","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":30,"title":["Heart Rate Variability and Accelerometry as Classification Tools for Monitoring Perceived Stress Levels\u2014A Pilot Study on Firefighters"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1652-6122","authenticated-orcid":false,"given":"Micha\u0142","family":"Meina","sequence":"first","affiliation":[{"name":"Faculty of Physics, Astronomy and Informatics, Department of Applied Informatics, Nicolaus Copernicus University in Toru\u0144, Grudzi\u0105dzka 5, 87-100 Torun, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6628-1955","authenticated-orcid":false,"given":"Ewa","family":"Ratajczak","sequence":"additional","affiliation":[{"name":"Faculty of Physics, Astronomy and Informatics, Department of Applied Informatics, Nicolaus Copernicus University in Toru\u0144, Grudzi\u0105dzka 5, 87-100 Torun, Poland"},{"name":"Faculty of Philosophy and Social Sciences, Institute of Psychology, Nicolaus Copernicus University in Toru\u0144, Podmurna 74, 87-100 Torun, Poland"},{"name":"Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toru\u0144, Wile\u0144ska 4, 87-100 Torun, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0230-7973","authenticated-orcid":false,"given":"Maria","family":"Sadowska","sequence":"additional","affiliation":[{"name":"Faculty of Philosophy and Social Sciences, Institute of Psychology, Nicolaus Copernicus University in Toru\u0144, Podmurna 74, 87-100 Torun, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krzysztof","family":"Rykaczewski","sequence":"additional","affiliation":[{"name":"Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toru\u0144, Wile\u0144ska 4, 87-100 Torun, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joanna","family":"Dreszer","sequence":"additional","affiliation":[{"name":"Faculty of Philosophy and Social Sciences, Institute of Psychology, Nicolaus Copernicus University in Toru\u0144, Podmurna 74, 87-100 Torun, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5066-7493","authenticated-orcid":false,"given":"Bibianna","family":"Ba\u0142aj","sequence":"additional","affiliation":[{"name":"Faculty of Philosophy and Social Sciences, Institute of Psychology, Nicolaus Copernicus University in Toru\u0144, Podmurna 74, 87-100 Torun, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stanis\u0142aw","family":"Biedugnis","sequence":"additional","affiliation":[{"name":"Institute of Safety Engineering, The Main School of Fire Service, S\u0142owackiego 52\/54, 01-629 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7465-0212","authenticated-orcid":false,"given":"Wojciech","family":"W\u0119grzy\u0144ski","sequence":"additional","affiliation":[{"name":"Fire Research Department, Building Research Institute (ITB), 00-611 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9546-2336","authenticated-orcid":false,"given":"Adam","family":"Krasuski","sequence":"additional","affiliation":[{"name":"Institute of Safety Engineering, The Main School of Fire Service, S\u0142owackiego 52\/54, 01-629 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.jemermed.2005.08.008","article-title":"Impact of post-traumatic stress disorder and job-related stress on burnout: A study of fire service workers","volume":"31","author":"Mitani","year":"2006","journal-title":"J. Emerg. Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1023\/A:1024461920456","article-title":"Exposure to duty-related incident stressors in urban firefighters and paramedics","volume":"11","author":"Beaton","year":"1998","journal-title":"J. Trauma. Stress"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1080\/02678379508256889","article-title":"Perceptions of work stress in Australian firefighters","volume":"9","author":"Moran","year":"1995","journal-title":"Work Stress"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1093\/occmed\/kqv144","article-title":"The relationship between burnout, PTSD symptoms and injuries in firefighters","volume":"66","author":"Katsavouni","year":"2016","journal-title":"Occup. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1080\/02678370600679512","article-title":"Prevalence of posttraumatic stress disorder symptoms in firefighters","volume":"20","author":"Scotti","year":"2006","journal-title":"Work Stress"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1002\/jts.22035","article-title":"The strongest correlates of PTSD for firefighters: Number, recency, frequency, or perceived threat of traumatic events?","volume":"28","author":"Pinto","year":"2015","journal-title":"J. Trauma. Stress"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1037\/1076-8998.4.2.131","article-title":"Exposure to traumatic incidents and prevalence of posttraumatic stress symptomatology in urban firefighters in two countries","volume":"4","author":"Corneil","year":"1999","journal-title":"J. Occup. Health Psychol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1289","DOI":"10.1007\/s11136-007-9248-7","article-title":"The relationship between quality of life and posttraumatic stress disorder or major depression for firefighters in Kaohsiung, Taiwan","volume":"16","author":"Chen","year":"2007","journal-title":"Qual. Life Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1017\/S1049023X00040218","article-title":"Sources of occupational stress among firefighter\/EMTs and firefighter\/paramedics and correlations with job-related outcomes","volume":"8","author":"Beaton","year":"1993","journal-title":"Prehospital Disaster Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"67","DOI":"10.5271\/sjweh.1819","article-title":"Psychological and psychophysiological effects of shift work","volume":"16","year":"1990","journal-title":"Scand. J. Work. Environ. Health"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1093\/occmed\/kqu133","article-title":"Physical and psychological determinants of injury in Ontario forest firefighters","volume":"64","author":"Gordon","year":"2014","journal-title":"Occup. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1177\/001872089403600208","article-title":"Fatigue and the shiftworker: Firefighters working on a rotating shift schedule","volume":"36","author":"Paley","year":"1994","journal-title":"Hum. Factors"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/j.jpsychires.2016.10.014","article-title":"PTSD symptoms and suicidal thoughts and behaviors among firefighters","volume":"84","author":"Boffa","year":"2017","journal-title":"J. Psychiatr. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1080\/02678370310001625649","article-title":"A preliminary investigation of post-traumatic stress symptoms among firefighters","volume":"17","author":"Haslam","year":"2003","journal-title":"Work Stress"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1186\/1476-069X-2-14","article-title":"Firefighters and on-duty deaths from coronary heart disease: A case control study","volume":"2","author":"Kales","year":"2003","journal-title":"Environ. Health"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1097\/CRD.0b013e318215c105","article-title":"Cardiovascular disease in US firefighters: A systematic review","volume":"19","author":"Soteriades","year":"2011","journal-title":"Cardiol. Rev."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Gomes, P., Kaiseler, M., Lopes, B., Faria, S., Queiros, C., and Coimbra, M. (2013, January 3\u20137). Are standard heart rate variability measures associated with the self-perception of stress of firefighters in action?. Proceedings of the 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Osaka, Japan.","DOI":"10.1109\/EMBC.2013.6610065"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1171","DOI":"10.1016\/j.aap.2010.12.030","article-title":"Line-of-duty deaths among US firefighters: An analysis of fatality investigations","volume":"43","author":"Kunadharaju","year":"2011","journal-title":"Accid. Anal. Prev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"440","DOI":"10.1097\/JCN.0000000000000165","article-title":"The prevalence of clinical and electrocardiographic risk factors of cardiovascular death among on-duty professional firefighters","volume":"30","author":"Carey","year":"2015","journal-title":"J. Cardiovasc. Nurs."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1017\/S1049023X17007026","article-title":"The influence of exposure to natural disasters on depression and PTSD symptoms among firefighters","volume":"33","author":"Pennington","year":"2018","journal-title":"Prehospital Disaster Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1938","DOI":"10.2105\/AJPH.94.11.1938","article-title":"Risk of hospitalization among firefighters: The national health interview survey, 1986\u20131994","volume":"94","author":"Lee","year":"2004","journal-title":"Am. J. Public Health"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1002\/smi.974","article-title":"Social support, self-efficacy and trauma in new recruits and experienced firefighters","volume":"19","author":"Regehr","year":"2003","journal-title":"Stress Health"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1093\/abm\/16.3.199","article-title":"Ecological momentary assessment (EMA) in behavorial medicine","volume":"16","author":"Stone","year":"1994","journal-title":"Ann. Behav. Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1111\/j.1745-6916.2007.00051.x","article-title":"Psychology as the science of self-reports and finger movements: Whatever happened to actual behavior?","volume":"2","author":"Baumeister","year":"2007","journal-title":"Perspect. Psychol. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1002\/smi.2496","article-title":"The multitasking framework: The effects of increasing workload on acute psychobiological stress reactivity","volume":"30","author":"Wetherell","year":"2014","journal-title":"Stress Health"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"H874","DOI":"10.1152\/ajpheart.00856.2009","article-title":"Physical activity and heart rate variability measured simultaneously during waking hours","volume":"298","author":"Hautala","year":"2010","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1249\/mss.0b013e31815a51b3","article-title":"Physical activity in the United States measured by accelerometer","volume":"40","author":"Troiano","year":"2008","journal-title":"Med. Sci. Sport. Exerc."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1037\/0022-006X.72.2.341","article-title":"An ecological momentary assessment of relapse crises in dieting","volume":"72","author":"Carels","year":"2004","journal-title":"J. Consult. Clin. Psychol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1186\/1743-0003-2-2","article-title":"Advances in wearable technology and applications in physical medicine and rehabilitation","volume":"2","author":"Bonato","year":"2005","journal-title":"J. NeuroEng. Rehabil."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"252","DOI":"10.7861\/clinmedicine.13-3-252","article-title":"The digital patient","volume":"13","author":"Bonnici","year":"2013","journal-title":"Clin. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1049\/iet-com:20070046","article-title":"Body area network for wireless patient monitoring","volume":"2","author":"Monton","year":"2008","journal-title":"Commun. IET"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/1743-0003-9-21","article-title":"A review of wearable sensors and systems with application in rehabilitation","volume":"9","author":"Patel","year":"2012","journal-title":"J. NeuroEng. Rehabil."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"23468","DOI":"10.1038\/srep23468","article-title":"A Flexible and Wearable Human Stress Monitoring Patch","volume":"6","author":"Yoon","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1097\/CIN.0000000000000011","article-title":"Research Methodology for Real-Time Stress Assessment of Nurses","volume":"31","author":"Milosevic","year":"2013","journal-title":"Comput. Inform. Nurs."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1040","DOI":"10.3389\/fpsyg.2014.01040","article-title":"A healthy heart is not a metronome: An integrative review of the heart\u2019s anatomy and heart rate variability","volume":"5","author":"Shaffer","year":"2014","journal-title":"Front. Psychol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Taelman, J., Vandeput, S., Spaepen, A., and Van Huffel, S. (2008, January 23\u201327). Influence of mental stress on heart rate and heart rate variability. Proceedings of the 4th European Conference of the International Federation for Medical and Biological Engineerin, Antwerp, Belgium.","DOI":"10.1007\/978-3-540-89208-3_324"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"517","DOI":"10.2165\/00007256-200333070-00004","article-title":"Heart rate monitoring","volume":"33","author":"Achten","year":"2003","journal-title":"Sport. Med."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1007\/BF02690935","article-title":"Psychological and physiological responses to stress: The right hemisphere and the hypothalamo-pituitary-adrenal axis, an inquiry into problems of human bonding","volume":"28","author":"Henry","year":"1993","journal-title":"Integr. Physiol. Behav. Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"803","DOI":"10.1007\/s00421-014-3066-8","article-title":"Short-and long-term reliability of heart rate variability indices during repetitive low-force work","volume":"115","author":"Hallman","year":"2015","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"7120","DOI":"10.3390\/s140407120","article-title":"Wearable biomedical measurement systems for assessment of mental stress of combatants in real time","volume":"14","author":"Seoane","year":"2014","journal-title":"Sensors"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"589","DOI":"10.2486\/indhealth.47.589","article-title":"Heart rate variability in occupational health-a systematic review","volume":"47","author":"Togo","year":"2009","journal-title":"Ind. Health"},{"key":"ref_42","first-page":"1","article-title":"Integrative evidence-based athlete assessment and intervention: A field-tested and validated protocol","volume":"1","author":"Carlstedt","year":"2007","journal-title":"J. Am. Board Sport Psychol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"McDuff, D., Gontarek, S., and Picard, R. (2014, January 26\u201330). Remote measurement of cognitive stress via heart rate variability. Proceedings of the 2014 36th Annual International Conference of the Engineering in Medicine and Biology Society (EMBC), Chicago, IL, USA.","DOI":"10.1109\/EMBC.2014.6944243"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1023\/A:1009598607998","article-title":"An examination of the relationship between resting heart rate variability and heart rate reactivity to a mental arithmetic stressor","volume":"25","author":"Sharpley","year":"2000","journal-title":"Appl. Psychophysiol. Biofeedback"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/S0167-8760(00)00085-4","article-title":"Heart rate variability, trait anxiety, and perceived stress among physically fit men and women","volume":"37","author":"Dishman","year":"2000","journal-title":"Int. J. Psychophysiol."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Kemp, A.H., Quintana, D.S., Felmingham, K.L., Matthews, S., and Jelinek, H.F. (2012). Depression, comorbid anxiety disorders, and heart rate variability in physically healthy, unmedicated patients: Implications for cardiovascular risk. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0030777"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.autneu.2008.11.010","article-title":"Reduced heart rate variability and vagal tone in anxiety: Trait versus state, and the effects of autogenic training","volume":"145","author":"Miu","year":"2009","journal-title":"Auton. Neurosci."},{"key":"ref_48","unstructured":"Wu, M., Cao, H., Nguyen, H.L., Surmacz, K., and Hargrove, C. (2015, January 25\u201329). Modeling perceived stress via HRV and accelerometer sensor streams. Proceedings of the 2015 37th Annual International Conference of the Engineering in Medicine and Biology Society (EMBC), Milan, Italy."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1007\/s11424-013-2287-y","article-title":"Heart rate variability during high-intensity exercise","volume":"26","author":"Sarmiento","year":"2013","journal-title":"J. Syst. Sci. Complex."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1894","DOI":"10.1097\/00005768-200011000-00012","article-title":"Resting heart rate variability in men varying in habitual physical activity","volume":"32","author":"Melanson","year":"2000","journal-title":"Med. Sci. Sport. Exerc."},{"key":"ref_51","first-page":"1053","article-title":"Automatic stress detection in working environments from smartphones\u2019 accelerometer data: A first step","volume":"20","author":"Osmani","year":"2015","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"R1","DOI":"10.1088\/0967-3334\/25\/2\/R01","article-title":"Accelerometry: Providing an integrated, practical method for long-term, ambulatory monitoring of human movement","volume":"25","author":"Mathie","year":"2004","journal-title":"Physiol. Meas."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1109\/TITB.2005.856864","article-title":"Implementation of a real-time human movement classifier using a triaxial accelerometer for ambulatory monitoring","volume":"10","author":"Karantonis","year":"2006","journal-title":"IEEE Trans. Inf. Technol. Biomed."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"1154","DOI":"10.3390\/s100201154","article-title":"Machine learning methods for classifying human physical activity from on-body accelerometers","volume":"10","author":"Mannini","year":"2010","journal-title":"Sensors"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"250","DOI":"10.2174\/1745017901814010250","article-title":"Wearable Biomonitoring Platform for the Assessment of Stress and its Impact on Cognitive Performance of Firefighters: An Experimental Study","volume":"14","author":"Rodrigues","year":"2018","journal-title":"Clin. Pract. Epidemiol. Ment. Heal. CP EMH"},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Rodrigues, S., Dias, D., Paiva, J.S., and Cunha, J.P. (2018, January 17\u201321). Psychophysiological Stress Assessment Among On-Duty Firefighters. Proceedings of the 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Honolulu, HI, USA.","DOI":"10.1109\/EMBC.2018.8513250"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"e5967","DOI":"10.7717\/peerj.5967","article-title":"Stress among on-duty firefighters: An ambulatory assessment study","volume":"6","author":"Rodrigues","year":"2018","journal-title":"PeerJ."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Pluntke, U., Gerke, S., Sridhar, A., Weiss, J., and Michel, B. (2019, January 23\u201327). Evaluation and classification of Physical and Psychological Stress in Firefighters using Heart Rate Variability. Proceedings of the 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Berlin, Germany.","DOI":"10.1109\/EMBC.2019.8856596"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.jtherbio.2014.10.003","article-title":"Firefighter feedback during active cooling: A useful tool for heat stress management?","volume":"46","author":"Savage","year":"2014","journal-title":"J. Therm. Biol."},{"key":"ref_60","unstructured":"Tharion, W.J., Buller, M.J., Clements, C.M., Dominguez, D., Sampsonis, C., Mullen, S.P., Karis, A.J., and Potter, A.W. (2013). Human Factors Evaluation of the Hidalgo Equivital EQ-02 Physiological Status Monitoring System, Army Research Institute of Environmental Medicine. DTIC Document."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1109\/10.83591","article-title":"Applications of adaptive filtering to ECG analysis: Noise cancellation and arrhythmia detection","volume":"38","author":"Thakor","year":"1991","journal-title":"Biomed. Eng. IEEE Trans."},{"key":"ref_62","doi-asserted-by":"crossref","unstructured":"Bao, L., and Intille, S. (2004). Activity recognition from user-annotated acceleration data. Pervasive Computing, Springer.","DOI":"10.1007\/978-3-540-24646-6_1"},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1007\/978-3-319-09912-5_29","article-title":"Towards Robust Framework for On-line Human Activity Reporting Using Accelerometer Readings","volume":"Volume 8610","author":"Schaefer","year":"2014","journal-title":"Active Media Technology"},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1111\/j.1469-8986.1997.tb02140.x","article-title":"Heart rate variability: Origins, methods, and interpretive caveats","volume":"34","author":"Berntson","year":"1997","journal-title":"Psychophysiology"},{"key":"ref_65","first-page":"1341","article-title":"Advances in heart rate variability signal analysis: Joint position statement by the e-Cardiology ESC Working Group and the European Heart Rhythm Association co-endorsed by the Asia Pacific Heart Rhythm Society","volume":"17","author":"Sassi","year":"2015","journal-title":"EP Eur."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/srep16619","article-title":"We should be using nonlinear indices when relating heart-rate dynamics to cognition and mood","volume":"5","author":"Young","year":"2015","journal-title":"Sci. Rep."},{"key":"ref_67","first-page":"514","article-title":"Heart rate variability: A noninvasive electrocardiographic method to measure the autonomic nervous system","volume":"134","author":"Sztajzel","year":"2004","journal-title":"Swiss Med. Wkly."},{"key":"ref_68","doi-asserted-by":"crossref","unstructured":"Electrophysiology, Task Force of the European Society of Cardiology the North American Society of Pacing (1996). Heart rate variability: Standards of measurement, physiological interpretation, and clinical use. Circulation, 93, 1043\u20131065.","DOI":"10.1161\/01.CIR.93.5.1043"},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.cmpb.2017.06.018","article-title":"Heart rate variability metrics for fine-grained stress level assessment","volume":"148","author":"Pereira","year":"2017","journal-title":"Comput. Methods Programs Biomed."},{"key":"ref_70","unstructured":"Lazarus, R.S., and Folkman, S. (1984). Stress, Appraisal, and Coping, Springer Publishing Company."},{"key":"ref_71","unstructured":"Gist, R., Taylor, V.H., and Raak, S. (2011). Suicide Surveillance, Prevention, and Intervention Measures for the US Fire Service: Findings and Recommendations for the Suicide and Depression Summit, National Fallen Firefighters Foundation."},{"key":"ref_72","unstructured":"Wilmoth, J. (2014). Trouble in mind. Special report: Firefighter behavioral health. NFPA J."},{"key":"ref_73","unstructured":"Brown, C. (2013). Are We Becoming More Socially Awkward? An Analysis of the Relationship Between Technological Communication Use and Social Skills in College Students. Psychology Honors Papers, Connecticut College."},{"key":"ref_74","doi-asserted-by":"crossref","unstructured":"Krasuski, A., Jankowski, A., Skowron, A., and Slezak, D. (2013, January 17\u201320). From sensory data to decision making: A perspective on supporting a fire commander. Proceedings of the 2013 IEEE\/WIC\/ACM International Joint Conferences on Web Intelligence (WI) and Intelligent Agent Technologies (IAT), Atlanta, GA, USA.","DOI":"10.1109\/WI-IAT.2013.188"},{"key":"ref_75","doi-asserted-by":"crossref","unstructured":"Krasuski, A. (2014, January 7\u201310). A framework for Dynamic Analytical Risk Management at the emergency scene. From tribal to top down in the risk management maturity model. Proceedings of the Federated Conference on Computer Science and Information Systems (FedCSIS), Warsaw, Poland.","DOI":"10.15439\/2014F371"},{"key":"ref_76","unstructured":"Bundesamt fur Bevolkerungsschutz und Katastrophenhilfe, FwDv100 (1999). Fuhrung und Leitung im Einsatz: Fuhrungssystem, Boorberg-Verlag."},{"key":"ref_77","unstructured":"Graeger, A., Cimolino, U., de Vries, H., and S\u00fcmersen, J. (2009). Einsatz-und Abschnittsleitung: Das Einsatz- F\u00fchrungs-System (EFS), Ecomed Sicherheit."},{"key":"ref_78","unstructured":"Department of Communities and Local Goverment (2008). Fire Service Operations, Incident Command, Fire Service Manual. [3rd ed.]."},{"key":"ref_79","doi-asserted-by":"crossref","unstructured":"Meina, M., Janusz, A., Rykaczewski, K., Slezak, D., Celmer, B., and Krasuski, A. (2015, January 13\u201316). Tagging firefighter activities at the emergency scene: Summary of AAIA\u201915 data mining competition at Knowledge Pit. Proceedings of the Computer Science and Information Systems (FedCSIS), 2015 Federated Conference on IEEE, Lodz, Poland.","DOI":"10.15439\/2015F426"},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1097\/PSY.0000000000000133","article-title":"Ethnic differences in resting heart rate variability: A systematic review and meta-analysis","volume":"77","author":"Hill","year":"2015","journal-title":"Psychosom. Med."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"906","DOI":"10.1016\/S0002-9149(99)80260-4","article-title":"Age, race, and sex differences in autonomic cardiac function measured by spectral analysis of heart rate variability\u2014The ARIC study","volume":"76","author":"Liao","year":"1995","journal-title":"Am. J. Cardiol."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"1856","DOI":"10.1249\/01.mss.0000175867.98628.27","article-title":"Heart rate variability in adolescents: Relations to physical activity, fitness, and adiposity","volume":"37","author":"Gutin","year":"2005","journal-title":"Med. Sci. Sport. Exerc."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1016\/j.neubiorev.2016.03.007","article-title":"Sex differences in healthy human heart rate variability: A meta-analysis","volume":"64","author":"Koenig","year":"2016","journal-title":"Neurosci. Biobehav. Rev."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1186\/s13293-015-0046-6","article-title":"Sex differences in autonomic function following maximal exercise","volume":"6","author":"Kappus","year":"2015","journal-title":"Biol. Sex Differ."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1139\/H10-028","article-title":"Sex differences in linear and nonlinear heart rate variability during early recovery from supramaximal exercise","volume":"35","author":"Mendonca","year":"2010","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1007\/s10484-015-9295-8","article-title":"Gender plays significant role in short-term heart rate variability","volume":"40","author":"Woo","year":"2015","journal-title":"Appl. Psychophysiol. Biofeedback"},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"215","DOI":"10.2114\/jpa.23.215","article-title":"Cardiovascular reactivity to mental stress: Relationship with menstrual cycle and gender","volume":"23","author":"Sato","year":"2004","journal-title":"J. Physiol. Anthropol. Appl. Hum. Sci."},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1002\/jts.22180","article-title":"Duty-Related Trauma Exposure and Posttraumatic Stress Symptoms in Professional Firefighters","volume":"30","author":"Lee","year":"2017","journal-title":"J. Trauma. Stress"},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1097\/00005053-199504000-00014","article-title":"Posttraumatic stress in volunteer firefighters: Predictors of distress","volume":"183","author":"Bryant","year":"1995","journal-title":"J. Nerv. Ment. Dis."},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1186\/s13728-016-0049-x","article-title":"Chronic occupational exposures can influence the rate of PTSD and depressive disorders in first responders and military personnel","volume":"5","author":"Walker","year":"2016","journal-title":"Extrem. Physiol. Med."},{"key":"ref_91","doi-asserted-by":"crossref","first-page":"1857","DOI":"10.1016\/j.patcog.2005.01.025","article-title":"Clustering of time series data\u2014A survey","volume":"38","author":"Liao","year":"2005","journal-title":"Pattern Recognit."},{"key":"ref_92","doi-asserted-by":"crossref","first-page":"3605","DOI":"10.1016\/j.patcog.2010.04.019","article-title":"Comparative study on classifying human activities with miniature inertial and magnetic sensors","volume":"43","author":"Altun","year":"2010","journal-title":"Pattern Recognit."},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1109\/TBCAS.2011.2160540","article-title":"Sensor positioning for activity recognition using wearable accelerometers","volume":"5","author":"Atallah","year":"2011","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_94","unstructured":"MacQueen, J. (1967). Some methods for classification and analysis of multivariate observations. Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability, Volume 1: Statistics, University of California Press."},{"key":"ref_95","doi-asserted-by":"crossref","unstructured":"Sculley, D. (2010, January 26\u201330). Web-scale K-means Clustering. Proceedings of the 19th International Conference on World Wide Web, Raleigh, NC, USA.","DOI":"10.1145\/1772690.1772862"},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"6474","DOI":"10.3390\/s140406474","article-title":"Window Size Impact in Human Activity Recognition","volume":"14","author":"Banos","year":"2014","journal-title":"Sensors"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/10\/2834\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:29:28Z","timestamp":1760174968000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/10\/2834"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,5,16]]},"references-count":96,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2020,5]]}},"alternative-id":["s20102834"],"URL":"https:\/\/doi.org\/10.3390\/s20102834","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,5,16]]}}}