HRV and Stress : A Mixed-Methods Approach for Comparison of Wearable Heart RateSensors for Biofeedback

Umair, Muhammad and Chalabianloo, Niaz and Sas, Corina and Ersoy, Cem (2021) HRV and Stress : A Mixed-Methods Approach for Comparison of Wearable Heart RateSensors for Biofeedback. IEEE Access, 9. pp. 14005-140024. ISSN 2169-3536

Abstract

Stress is one of the most significant health problems in today’s world. Existing work has usedheart rate variability (HRV) to detect stress and provide biofeedback in order to regulate it. There has beena growing interest in using wearable biosensors to measure HRV. Each of these sensors acquires heart ratedata using different technologies for various bodily locations, therefore posing a challenge for researchersto decide upon a particular device in a research experiment. Previous work has only compared differentsensing devices against a gold standard in terms of data quality, thus overlooking qualitative analysis for theusability and acceptability of such devices. This paper introduces a mixed-methods approach to comparethe data quality and user acceptance of the six most common wearable heart rate monitoring biosensors.We conducted a 70-minute data collection procedure to obtain HRV data from 32 participants followed bya 10-minute semi-structured interview on sensors’ wearability and comfort, long-term use, aesthetics, andsocial acceptance. We performed quantitative analysis consisting of correlation and agreement analysis onthe HRV data and thematic analysis on qualitative data obtained from interviews. Our results show that theelectrocardiography (ECG) chest strap achieved the highest correlation and agreement levels in all sessionsand had the lowest amount of artifacts, followed by the photoplethysmography (PPG) wristband, ECG sensorboard kit and PPG smartwatch. In all three sessions, wrist-worn devices showed a lower amount of agreementand correlation with the reference device. Qualitative findings from interviews highlight that participantsprefer wrist and arm-worn devices in terms of aesthetics, wearability, and comfort, followed by chest-worndevices. Moreover, participants mentioned that the latter are more likely to invite social judgment fromothers, and they would not want to wear it in public. Participants preferred the chest strap for short-term useand the wrist and arm-worn sensors over long-time.