Comfort of Wrist-Worn Devices: Development of an Assessment Tool and Measurement of Comfort-Discomfort Pressure for Older and Younger Users

Wrist-worn devices hold significant potential for health monitoring, particularly for older people. However, the adoption and continuous usage of these devices are heavily affected by wearing comfort. Currently, there is still a lack of validated assessment tools specifically developed to evaluate the comfort of such devices. Additionally, while pressure is critical for both proper device placement and maintaining comfort, quantitative references for suitbale pressure levels are scarce. Moreover, the impact of age difference on comfort perceptions have been largely overlooked. To address these gaps, we conducted two experiments involving 18 older and 18 younger participants. In Experiment 1, we gathered comfort evaluations from participants while wearing the devices in both home/office and exercise scenarios. In Experiment 2, we focused on pressure, measuring the pressure on participants' wrists under three strap material conditions and collecting their corresponding comfort evaluations. The results established three dimensions of comfort: movement comfort, thermophysiological comfort, and contact comfort, with their relative importance varying by age and use scenario. Also, we identified comfort-discomfort pressure ranges for both age groups, highlighting the influence of strap material and age on comfort perceptions. These findings offer valuable design guidance for manufacturers and enhance understanding of wrist-mounted device comfort.