{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T10:05:36Z","timestamp":1790244336045,"version":"4.1.0"},"reference-count":19,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T00:00:00Z","timestamp":1790208000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004242","name":"Princess Nourah bint Abdulrahman University","doi-asserted-by":"publisher","award":["PNURSP2026R209"],"award-info":[{"award-number":["PNURSP2026R209"]}],"id":[{"id":"10.13039\/501100004242","id-type":"DOI","asserted-by":"publisher"}]},{"award":["PNURSP2026R209"],"award-info":[{"award-number":["PNURSP2026R209"]}],"id":[{"id":"https:\/\/ror.org\/05b0cyh02","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Continuous remote physiological monitoring requires low-cost sensing nodes to preserve timing fidelity while maintaining secure connectivity and interpretable escalation. This study presents an engineering proof-of-concept platform centered on an ESP32-S3 with AD8232 ECG, MAX30102 PPG\/SpO2, and MAX30205 contact-temperature sensing. FreeRTOS separates nominal 100 Hz ECG\/PPG acquisition from network communication, and the ECG R-wave-to-peripheral-PPG-foot interval is treated as pulse-arrival time (PAT). Telemetry is transmitted over authenticated HTTPS to a Laravel platform, while a separate FastAPI service provides human-in-the-loop normal\/warning\/critical functional triage. The current evidence is limited to bench-top engineering operation and synthetically constructed triage scenarios; no human-participant measurements are analyzed or reported. An ethics-approved rest-exertion-recovery protocol has been prepared for a future validation stage. The present results support system integration and engineering feasibility, while physiological accuracy, PAT-to-blood-pressure calibration, respiratory-rate agreement, classifier performance, timing reliability, and battery\/power characteristics remain to be established quantitatively.<\/jats:p>","DOI":"10.3390\/s26196047","type":"journal-article","created":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T09:07:54Z","timestamp":1790240874000},"page":"6047","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["ESP32-S3-Based Multimodal Wearable for Remote Vital-Sign Acquisition with ECG-to-PPG Pulse-Arrival-Time Tracking and Functional Cloud Triage: An Engineering Proof of Concept"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8621-4410","authenticated-orcid":false,"given":"Mohamed Ali","family":"Torad","sequence":"first","affiliation":[{"name":"Department of Electronics and Communication Engineering, Higher Technological Institute (HTI), 10th of Ramadan City 44634, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hamdy Elsayed","family":"Ahmed","sequence":"additional","affiliation":[{"name":"Department of Electronics and Communication Engineering, Higher Technological Institute (HTI), 10th of Ramadan City 44634, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4170-6694","authenticated-orcid":false,"given":"Ahmed Ali Mohamed","family":"Torad","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy and Health Rehabilitation, Jouf University, Sakaka 72341, Saudi Arabia"},{"name":"Department of Basic Sciences, Faculty of Physical Therapy, Kafrelsheikh University, Kafrelsheikh 33516, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9080-5061","authenticated-orcid":false,"given":"Mona Mohamed","family":"Taha","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Sciences, College of Health and Rehabilitation Sciences, Princess Nourah Bint Abdulrahman University, P.O. 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Available online: https:\/\/laravel.com\/docs."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/19\/6047\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T09:16:58Z","timestamp":1790241418000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/19\/6047"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,24]]},"references-count":19,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["s26196047"],"URL":"https:\/\/doi.org\/10.3390\/s26196047","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,24]]}}}