Sleep Tracking of a Commercially Available Smart Ring and Smartwatch Against Medical-Grade Actigraphy in Everyday Settings: Instrument Validation Study

Milad Asgari Mehrabadi   ¹ , BSc, MSc ;   Iman Azimi   ² , PhD ;   Fatemeh Sarhaddi   ² , BSc, MSc ;   Anna Axelin   ^{3, 4} , PhD ;   Hannakaisa Niela-Vilén   ³ , PhD ;   Saana Myllyntausta   ^{5, 6, 7} , PhD ;   Sari Stenholm   ^{5, 7} , PhD ;   Nikil Dutt   ^{1, 8} , PhD ;   Pasi Liljeberg   ² , PhD ;   Amir M Rahmani   ^{1, 8, 9} , PhD, MBA

¹ Department of Electrical Engineering and Computer Science, University of California Irvine, Irvine, CA, United States

² Department of Computing, University of Turku, Turku, Finland

³ Department of Nursing Science, University of Turku, Turku, Finland

⁴ Department of Obstetrics and Gynaecology, Turku University Hospital, Turku, Finland

⁵ Department of Public Health, University of Turku and Turku University Hospital, Turku, Finland

⁶ School of Educational Sciences and Psychology, University of Eastern Finland, Joensuu, Kuopio, Finland

⁷ Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland

⁸ Department of Computer Science, University of California Irvine, Irvine, CA, United States

⁹ School of Nursing, University of California Irvine, Irvine, CA, United States