Evaluating the Accuracy of Wearable Sensors to Measure Heart Rate Variability

Hanna O'Savage*, Rondalyn Whitney and Elliott Theeke, Division of Occupational Therapy, West Virginia University, Morgantown, WV 26506

Field (Broad Category): Occupational Therapy (Health Sciences) 

Student’s Major: Occupational Therapy 

Wearable sensor technology (WST) is becoming an increasingly popular way for people to make personal health decisions. However, there is little research beyond product marketing on the accuracy of wearable sensors, specifically for those measuring heart rate variability (HRV) as a proxy for stress. The purpose of this study is to compare the accuracy of HRV as measured by three devices. This study is critical evidence as more people are using wearable sensors and HRV as a measure of stress. Thirty-two participants performed three tasks wearing three different wearable sensors. The three tasks included sitting (at rest), playing a game (sitting active), and walking up two flights of stairs carrying a twenty-five-pound bag of rice (MET 6). The three devices included the LETSCOM Fitness Tracker, the Garmin Vivosmart, and the medical-grade Polar A300 chest monitor. HRV was recorded before, during, and after each activity from each wearable sensor worn by participants. At rest, the three wearable sensors did not produce significantly different results. During the board game activity, the LETSCOM Fitness Tracker was less accurate in measuring HRV compared to the Garmin Vivosmart and Polar A300. The Garmin Vivosmart and LETSCOM Fitness Tracker were each less accurate than the Polar A300 during the active portion of the procedure. Our study provides the first measure of accuracy for wearable sensor technology. Commercially available measures of HRV provide accurate measures of stress when at rest, but lose accuracy when engaged in activity, especially during exercise. 

Funding: Start Up funds for Dr. Rondalyn Whitney, Division of Occupational Therapy, SOM 

Program/mechanism supporting research/creative efforts: WVU's Research Apprenticeship Program (RAP) & accompanying HONR 297-level course