{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T03:26:51Z","timestamp":1776914811699,"version":"3.51.2"},"reference-count":37,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2024,1,8]],"date-time":"2024-01-08T00:00:00Z","timestamp":1704672000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Singapore Ministry of Education (MOE) Academic Research Fund (AcRF) Tier 1 grant","award":["22-SIS-SMU-051"],"award-info":[{"award-number":["22-SIS-SMU-051"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Heart rate is a key vital sign that can be used to understand an individual\u2019s health condition. Recently, remote sensing techniques, especially acoustic-based sensing, have received increasing attention for their ability to non-invasively detect heart rate via commercial mobile devices such as smartphones and smart speakers. However, due to signal interference, existing methods have primarily focused on monitoring a single user and required a large separation between them when monitoring multiple people. These limitations hinder many common use cases such as couples sharing the same bed or two or more people located in close proximity. In this paper, we present an approach that can minimize interference and thereby enable simultaneous heart rate monitoring of multiple individuals in close proximity using a commonly available smart speaker prototype. Our user study, conducted under various real-life scenarios, demonstrates the system\u2019s accuracy in sensing two users\u2019 heart rates when they are seated next to each other with a median error of 0.66 beats per minute (bpm). Moreover, the system can successfully monitor up to four people in close proximity.<\/jats:p>","DOI":"10.3390\/s24020382","type":"journal-article","created":{"date-parts":[[2024,1,8]],"date-time":"2024-01-08T07:59:20Z","timestamp":1704700760000},"page":"382","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Remote Multi-Person Heart Rate Monitoring with Smart Speakers: Overcoming Separation Constraint"],"prefix":"10.3390","volume":"24","author":[{"given":"Thu","family":"Tran","sequence":"first","affiliation":[{"name":"School of Computing and Information Systems, Singapore Management University, Singapore 178902, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dong","family":"Ma","sequence":"additional","affiliation":[{"name":"School of Computing and Information Systems, Singapore Management University, Singapore 178902, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rajesh","family":"Balan","sequence":"additional","affiliation":[{"name":"School of Computing and Information Systems, Singapore Management University, Singapore 178902, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1031","DOI":"10.1007\/s11517-006-0119-0","article-title":"Heart rate variability: A review","volume":"44","author":"Acharya","year":"2006","journal-title":"Med Biol. 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