{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,9]],"date-time":"2026-02-09T13:37:54Z","timestamp":1770644274936,"version":"3.49.0"},"reference-count":50,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2018,9,14]],"date-time":"2018-09-14T00:00:00Z","timestamp":1536883200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002706","name":"AFA F\u00f6rs\u00e4kring","doi-asserted-by":"publisher","award":["150039"],"award-info":[{"award-number":["150039"]}],"id":[{"id":"10.13039\/501100002706","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100010686","name":"European Institute of Innovation and Technology","doi-asserted-by":"publisher","award":["18454"],"award-info":[{"award-number":["18454"]}],"id":[{"id":"10.13039\/100010686","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004543","name":"China Scholarship Council","doi-asserted-by":"publisher","award":["201408060249"],"award-info":[{"award-number":["201408060249"]}],"id":[{"id":"10.13039\/501100004543","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper presents a new method that integrates heart rate, respiration, and motion information obtained from a wearable sensor system to estimate energy expenditure. The system measures electrocardiography, impedance pneumography, and acceleration from upper and lower limbs. A multilayer perceptron neural network model was developed, evaluated, and compared to two existing methods, with data from 11 subjects (mean age, 27 years, range, 21\u201365 years) who performed a 3-h protocol including submaximal tests, simulated work tasks, and periods of rest. Oxygen uptake was measured with an indirect calorimeter as a reference, with a time resolution of 15 s. When compared to the reference, the new model showed a lower mean absolute error (MAE = 1.65 mL\/kg\/min, R2 = 0.92) than the two existing methods, i.e., the flex-HR method (MAE = 2.83 mL\/kg\/min, R2 = 0.75), which uses only heart rate, and arm-leg HR+M method (MAE = 2.12 mL\/kg\/min, R2 = 0.86), which uses heart rate and motion information. As indicated, this new model may, in combination with a wearable system, be useful in occupational and general health applications.<\/jats:p>","DOI":"10.3390\/s18093092","type":"journal-article","created":{"date-parts":[[2018,9,14]],"date-time":"2018-09-14T10:57:59Z","timestamp":1536922679000},"page":"3092","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":44,"title":["Fusion of Heart Rate, Respiration and Motion Measurements from a Wearable Sensor System to Enhance Energy Expenditure Estimation"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3256-9029","authenticated-orcid":false,"given":"Ke","family":"Lu","sequence":"first","affiliation":[{"name":"School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, H\u00e4lsov\u00e4gen 11C, 141 57 Huddinge, Sweden"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7285-824X","authenticated-orcid":false,"given":"Liyun","family":"Yang","sequence":"additional","affiliation":[{"name":"School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, H\u00e4lsov\u00e4gen 11C, 141 57 Huddinge, Sweden"},{"name":"Institute of Environmental Medicine, Karolinska Institutet, Solnav\u00e4gen 1, 171 77 Solna, Sweden"}]},{"given":"Fernando","family":"Seoane","sequence":"additional","affiliation":[{"name":"Department of Clinical Science, Intervention and Technology, Karolinska Institutet, H\u00e4lsov\u00e4gen 7, 141 57 Huddinge, Sweden"},{"name":"Swedish School of Textiles, University of Bor\u00e5s, All\u00e9gatan 1, 501 90 Bor\u00e5s, Sweden"},{"name":"Department of Biomedical Engineering, Karolinska University Hospital, 1, 171 76 Solna, Sweden"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7807-8682","authenticated-orcid":false,"given":"Farhad","family":"Abtahi","sequence":"additional","affiliation":[{"name":"School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, H\u00e4lsov\u00e4gen 11C, 141 57 Huddinge, Sweden"},{"name":"Institute of Environmental Medicine, Karolinska Institutet, Solnav\u00e4gen 1, 171 77 Solna, Sweden"}]},{"given":"Mikael","family":"Forsman","sequence":"additional","affiliation":[{"name":"School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, H\u00e4lsov\u00e4gen 11C, 141 57 Huddinge, Sweden"},{"name":"Institute of Environmental Medicine, Karolinska Institutet, Solnav\u00e4gen 1, 171 77 Solna, Sweden"}]},{"given":"Kaj","family":"Lindecrantz","sequence":"additional","affiliation":[{"name":"Institute of Environmental Medicine, Karolinska Institutet, Solnav\u00e4gen 1, 171 77 Solna, Sweden"},{"name":"Swedish School of Textiles, University of Bor\u00e5s, All\u00e9gatan 1, 501 90 Bor\u00e5s, Sweden"}]}],"member":"1968","published-online":{"date-parts":[[2018,9,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1080\/00140130210123499","article-title":"Relationship between Maximum Acceptable Work Time and Physical Workload","volume":"45","author":"Wu","year":"2002","journal-title":"Ergonomics"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2065","DOI":"10.2337\/dc16-1728","article-title":"Physical Activity\/Exercise and Diabetes: A Position Statement of the American Diabetes Association","volume":"39","author":"Colberg","year":"2016","journal-title":"Diabetes Care"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2785","DOI":"10.1007\/s00421-011-2268-6","article-title":"Measurement of Human Energy Expenditure, with Particular Reference to Field Studies: An Historical Perspective","volume":"112","author":"Shephard","year":"2012","journal-title":"Eur. 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