{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,9]],"date-time":"2026-05-09T16:41:28Z","timestamp":1778344888597,"version":"3.51.4"},"reference-count":84,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2020,3,17]],"date-time":"2020-03-17T00:00:00Z","timestamp":1584403200000},"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>A wristwatch-based wireless sensor platform for IoT wearable health monitoring applications is presented. The paper describes the platform in detail, with a particular focus given to the design of a novel and compact wireless sub-system for 868 MHz wristwatch applications. An example application using the developed platform is discussed for arterial oxygen saturation (SpO2) and heart rate measurement using optical photoplethysmography (PPG). A comparison of the wireless performance in the 868 MHz and the 2.45 GHz bands is performed. Another contribution of this work is the development of a highly integrated 868 MHz antenna. The antenna structure is printed on the surface of a wristwatch enclosure using laser direct structuring (LDS) technology. At 868 MHz, a low specific absorption rate (SAR) of less than 0.1% of the maximum permissible limit in the simulation is demonstrated. The measured on-body prototype antenna exhibits a \u221210 dB impedance bandwidth of 36 MHz, a peak realized gain of \u22124.86 dBi and a radiation efficiency of 14.53% at 868 MHz. To evaluate the performance of the developed 868 MHz sensor platform, the wireless communication range measurements are performed in an indoor environment and compared with a commercial Bluetooth wristwatch device.<\/jats:p>","DOI":"10.3390\/s20061675","type":"journal-article","created":{"date-parts":[[2020,3,18]],"date-time":"2020-03-18T08:13:27Z","timestamp":1584519207000},"page":"1675","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":55,"title":["A Wristwatch-Based Wireless Sensor Platform for IoT Health Monitoring Applications"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2337-1376","authenticated-orcid":false,"given":"Sanjeev","family":"Kumar","sequence":"first","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1652-9262","authenticated-orcid":false,"given":"John L.","family":"Buckley","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0671-5678","authenticated-orcid":false,"given":"John","family":"Barton","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Melusine","family":"Pigeon","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2986-4382","authenticated-orcid":false,"given":"Robert","family":"Newberry","sequence":"additional","affiliation":[{"name":"Sanmina Corporation, 13000 S. Memorial Parkway, Huntsville, AL 35803, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Matthew","family":"Rodencal","sequence":"additional","affiliation":[{"name":"Sanmina Corporation, 13000 S. Memorial Parkway, Huntsville, AL 35803, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Adhurim","family":"Hajzeraj","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tim","family":"Hannon","sequence":"additional","affiliation":[{"name":"Sanmina Corporation, 13000 S. Memorial Parkway, Huntsville, AL 35803, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ken","family":"Rogers","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Declan","family":"Casey","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Donal","family":"O\u2019Sullivan","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5522-2597","authenticated-orcid":false,"given":"Brendan","family":"O\u2019Flynn","sequence":"additional","affiliation":[{"name":"Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP Cork, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Khan, R., Khan, S.U., Zaheer, R., and Khan, S. 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