Published on in Vol 8, No 11 (2020): November
![Sleep Tracking of a Commercially Available Smart Ring and Smartwatch Against Medical-Grade Actigraphy in Everyday Settings: Instrument Validation Study Sleep Tracking of a Commercially Available Smart Ring and Smartwatch Against Medical-Grade Actigraphy in Everyday Settings: Instrument Validation Study](https://asset.jmir.pub/assets/1f63f3a6a9007c9b1205460ded4c9cd3.png 480w,https://asset.jmir.pub/assets/1f63f3a6a9007c9b1205460ded4c9cd3.png 960w,https://asset.jmir.pub/assets/1f63f3a6a9007c9b1205460ded4c9cd3.png 1920w,https://asset.jmir.pub/assets/1f63f3a6a9007c9b1205460ded4c9cd3.png 2500w)
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