Reliability and Validation of the Hexoskin Wearable Bio-Collection Device During Walking Conditions

Abstract

To evaluate if the Hexoskin smart shirt (HxS) would produce valid and reliable measurements for heart rate (HR), respiratory rate (RR), minute ventilation (V_E), step count (SC), and energy expenditure (EE) when compared to a Polar T-31 heart rate monitor, an Applied Electrochemistry Moxus Metabolic System, and a manual step count. A two-day walking treadmill protocol with participants walking for 3 minutes at 3 speeds (1.5mph, 2.5mph, 3.5mph, 0% grade) was performed. Forty-nine volunteers participated the first day, forty-six on the second, thirty-one were used for reliability. Values calculated for the HxS data used Pearson's product-moment correlation (p < 0.05; r ≥ 0.70) for validity and Cronbach's α (≥ 0.70) for reliability. HxS HR (1.5mph; p<0.01, r=0.86, α=0.86. 2.5mph; p<0.01, r=0.81, α=0.88. 3.5mph; p<0.01, r=0.85, α=0.85), HxS RR (1.5mph; p<0.01, r=0.87, α=0.93. 2.5mph; p<0.01, r=0.86, α=0.92. 3.5mph; p<0.01, r=0.71, α=0.76), HxS V_E (1.5mph; p=0.66, r=0.11, α=0.70. 2.5mph; p=0.01, r=0.15, α=0.73. 3.5mph; p=0.31, r=0.08, α=0.14), HxS SC (1.5mph; p=0.90, r=-0.01, α=0.70. 2.5mph; p=0.22, r=0.13, α=0.86. 3.5mph; p<0.01, r=0.74, α=0.85), HxS EE (1.5mph; p<0.01, r=0.56, α=0.85. 2.5mph; p<0.01, r=0.50, α=0.83. 3.5mph; p<0.01, r=0.51, α=0.80). HxS HR and RR provided valid and reliable measures at all three speeds while V_E, SC, and EE had a mixture of results based on speed. These results are important in the use of the Hexoskin in an accurate manner for athletes, coaches, and for the potential medical applications being advocated in the field of telemedicine procedures.

Keywords: Hexoskin; reliability; treadmill; validity; wearable technology.