Accepted for/Published in: JMIR mHealth and uHealth
Date Submitted: Nov 25, 2023
Date Accepted: Oct 24, 2024
Reliability and accuracy of a photoplethysmography heart rate sensor: a validation study of the Fitbit Charge 4 in ecological conditions
ABSTRACT
Background:
The use of wrist-worn photoplethysmography (PPG) heart rate (HR) sensors has been quickly increasing over the recent years. Wearables could be useful for researchers and individuals for their simplicity to set up and use. However, only a limited number of studies investigated the reliability and accuracy of these devices in non-laboratory controlled conditions.
Objective:
The purpose of this study was (1) to assess the accuracy and reliability of the PPG based HR sensor of the Fitbit Charge 4 (FC4) in ecological condition; (2) to quantify the potential variability caused by the nature of the activity.
Methods:
HR was simultaneously collected during various sport sessions with the FC4 and a Polar H10, as criterion. Skin tone was assessed with Fitzpatrick Scale. Intraclass correlation coefficients (ICC), Lin’s concordance correlation coefficient (CCC) and Bland-Altman test determined reliability and accuracy of the sensor.
Results:
HR data of 26 students aged 21.1±5.8 years on averaged were recorded during 77.47 hours of physical activity. ICCs (and CCCs) for running and orienteering running were 0.900 (0.999) and 0.801 (0.932) respectively, whereas for badminton, tennis, bike and soccer, they were 0.365 (0.778), 0.421 (0.884), 0.658 (0.971) and 0.487 (0.809), respectively. Highest biases were found for badminton and soccer, whereas smallest was found for running.
Conclusions:
Researchers and individuals should not use the FC4 for measuring HR because of its LOA width and sensitivity to motion artifacts.
Citation
Request queued. Please wait while the file is being generated. It may take some time.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.