{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T18:45:54Z","timestamp":1781117154440,"version":"3.54.1"},"reference-count":27,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2020,7,30]],"date-time":"2020-07-30T00:00:00Z","timestamp":1596067200000},"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>Animal welfare remains a very important issue in the livestock sector, but monitoring animal welfare in an objective and continuous way remains a serious challenge. Monitoring animal welfare, based upon physiological measurements instead of the audio\u2013visual scoring of behaviour, would be a step forward. One of the obvious physiological signals related to welfare and stress is heart rate. The objective of this research was to measure heart rate (beat per minutes) in pigs with technology that soon will be affordable. Affordable heart rate monitoring is done today at large scale on humans using the Photo Plethysmography (PPG) technology. We used PPG sensors on a pig\u2032s body to test whether it allows the retrieval of a reliable heart rate signal. A continuous wavelet transform (CWT)-based algorithm is developed to decouple the cardiac pulse waves from the pig. Three different wavelets, namely second, fourth and sixth order Derivative of Gaussian (DOG), are tested. We show the results of the developed PPG-based algorithm, against electrocardiograms (ECG) as a reference measure for heart rate, and this for an anaesthetised versus a non-anaesthetised animal. We tested three different anatomical body positions (ear, leg and tail) and give results for each body position of the sensor. In summary, it can be concluded that the agreement between the PPG-based heart rate technique and the reference sensor is between 91% and 95%. In this paper, we showed the potential of using the PPG-based technology to assess the pig\u2032s heart rate.<\/jats:p>","DOI":"10.3390\/s20154251","type":"journal-article","created":{"date-parts":[[2020,7,31]],"date-time":"2020-07-31T04:15:31Z","timestamp":1596168931000},"page":"4251","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["An Approach towards Motion-Tolerant PPG-Based Algorithm for Real-Time Heart Rate Monitoring of Moving Pigs"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9986-5324","authenticated-orcid":false,"given":"Ali","family":"Youssef","sequence":"first","affiliation":[{"name":"Faculty of Bioscience Engineering, Katholieke Universiteit Leuven (KU LEUVEN), Kasteelpark Arenberg 30, 3001 Heverlee\/Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0578-1363","authenticated-orcid":false,"given":"Alberto","family":"Pe\u00f1a Fern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Faculty of Bioscience Engineering, Katholieke Universiteit Leuven (KU LEUVEN), Kasteelpark Arenberg 30, 3001 Heverlee\/Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Wassermann","sequence":"additional","affiliation":[{"name":"Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Svenja","family":"Biernot","sequence":"additional","affiliation":[{"name":"Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eva-Maria","family":"Wittauer","sequence":"additional","affiliation":[{"name":"Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3438-0254","authenticated-orcid":false,"given":"Andr\u00e9","family":"Bleich","sequence":"additional","affiliation":[{"name":"Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joerg","family":"Hartung","sequence":"additional","affiliation":[{"name":"University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2974-6055","authenticated-orcid":false,"given":"Daniel","family":"Berckmans","sequence":"additional","affiliation":[{"name":"Faculty of Bioscience Engineering, Katholieke Universiteit Leuven (KU LEUVEN), Kasteelpark Arenberg 30, 3001 Heverlee\/Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0161-3189","authenticated-orcid":false,"given":"Tomas","family":"Norton","sequence":"additional","affiliation":[{"name":"Faculty of Bioscience Engineering, Katholieke Universiteit Leuven (KU LEUVEN), Kasteelpark Arenberg 30, 3001 Heverlee\/Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,7,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1017\/S1751731113002140","article-title":"Welfare implication of measuring heart rate and heart rate variability in dairy cattle: literature review and conclusions for future research","volume":"8","author":"Kovacs","year":"2013","journal-title":"Animal"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"465","DOI":"10.4141\/cjas94-066","article-title":"Validation of a heart-rate monitor for measuring a stress response in dairy cows","volume":"74","author":"Hopster","year":"1994","journal-title":"Can. 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