Expected and Perceived Usability of a Wearable Device That Monitors Physiological Metrics

Wearable devices serve as a bridge between technology and human performance by providing objective physiological data for assessing warfighter readiness, health, and performance. Given their innovative nature and application in military operational settings, feedback from end users is crucial for determining the usability of wearable devices. Therefore, this study aimed to evaluate the usability and end-user comfort of the LifeLens device. Forty-seven participants wore the LifeLens device during the Intensive Trauma and Surgical Skills Course. Before the training, participants completed questionnaires on technology readiness and expected usability of the LifeLens device. The perceived usability of the LifeLens device was assessed at the end of the training. Wilcoxon signed-rank tests were conducted to evaluate differences in expected and perceived usability items pre- and post-training. Additionally, exploratory analyses were conducted to determine how technology readiness moderated the effect of expected and perceived usability items. Overall, participants reported positive expectations and perceptions regarding the usability of the LifeLens device. There were significant differences between expected and perceived usability in the aesthetic (z = -3.28, P = .001) and comfort (z = 3.27, P = .001) items. Finally, exploratory analyses revealed that technology readiness moderates the effect of pre- and post-training scores on acceptance (β = -0.87, SE = 0.25, P = 0.001), such that the positive relationship between pre- and post-training scores on acceptance was stronger among those who reported lower technology readiness opinions (β = 0.59, P < .001). These findings suggest that the LifeLens device is both usable and comfortable in a high-intensity training environment and support its continued use in military training to gather real-time physiological data for aiding in psychological and injury prevention efforts.