Automatic sleep-wake and nap analysis with a new wrist worn online activity monitoring device Vivago Wristcare

STUDY OBJECTIVE: Vivago WristCare is a new activity monitoring device, which allows long-term online monitoring of the activity of the user. This study evaluates the ability of the device to discriminate sleep/wake patterns during nighttime and during napping. DESIGN: Participants spent one night in the sleep laboratory where signals from polysomnography, actigraphy and WristCare were acquired. In addition, actigraphy and WristCare were used for 3-6 days for nap-analysis. SETTING: NA. PATIENTS OR PARTICIPANTS: Participants were 32 adults aged 26-89 years. The participants were studied in three study groups: all subjects, senior subjects (age > 65 years) and middle-aged subjects (age < 65 years). INTERVENTIONS: NA. RESULTS: Sleep/wake patterns were extracted from polysomnography, actigraphy and WristCare for the night slept in sleep laboratory. The agreement percents between the scorings of polysomnography and actigraphy, and between polysomnography and WristCare were about 80 % for all study groups. As total sleep time was estimated and the algorithm was optimized for this measure, the performance of the WristCare and actigraphy were similar. Both actigraphy and WristCare overestimated appreciably total sleep time (TST). Also in nap-analysis, actigraphy and WristCare performed similarly as the number of naps and the length of the naps were compared. CONCLUSIONS: The performance of the WristCare can be assumed to be well comparable to actigraphy in sleep/wake studies. The study suggests that the device may be used in long-term monitoring of sleep/wake patterns with similar performance to actigraphy.