Wrist gadgets track sleep in older people with dementia

Wrist-worn devices, particularly those that measure temperature, may help monitor sleep in older adults living with dementia (OAWD), according to a recent study. Nevertheless, current technologies seem to fall short, as they are easily disrupted by broken sleep patterns and body movements.

“As wearable technologies are increasingly being used by long-term care homes and healthy older adults to track sleep and inform sleep management and support, this research suggests that caution should be used when interpreting sleep data when monitoring the sleep of older adults, particularly those living with dementia,” the researchers said. “This highlights the need for future research and development to create systems that better complement older adult populations.”

Eight OAWDs participated in the study and were asked to wear the Mi Band 2, a commercially available smart wristband, along with a custom wristband developed by the investigators. All devices were worn on the left arm for 14 days. Parallel groups of 10 healthy young (aged 20–30 years) and older (aged ≥65 years) adults were also included and subjected to the same experimental protocol.

Sleep diaries were used as references for the sleep onset and offset times, as well as the number of night-time wake-ups and sleep quality.

Mi Band data showed significant deviations compared with sleep diary entries, particularly in OAWDs. Sleep onset time, for example, differed by an average of 253±104 minutes (p<0.001), while sleep offset measurements were off by 161±94 minutes (p<0.001). [JMIR Mhealth Uhealth 2021;9:e26462]

Device measurements of sleep duration seemed the least accurate, differing by 379±163 minutes relative to sleep diary entries (p<0.001).

Notably, wrist-worn measurements were much more accurate for the controls, only deviating from sleep diaries by 31–64 minutes in both the younger and older healthy controls.

The Mi Band device was also able to elucidate changes in temperature throughout the day. All three groups showed a similar pattern of higher temperatures during the day, which dropped down at night and during the early morning. Temperature measurements ranged from just below 32 ^oC to just above 35 ^oC.

The older and younger healthy controls had nearly identical temperature curves. OAWDs, on the other hand, tended to have the flattest curve, with higher night-time and lower daytime body temperatures.

In terms of sleep movement, actigraphy showed that older adults tended to have greater night-time movement than younger comparators, an effect that was particularly strong among participants with dementia.

“This research adds evidence that wrist temperature can be used as an indicator of sleep status, including for OAWD and people with irregular sleep patterns,” the researchers said. “As illustrated by case studies from our data, suboptimal sleep detection performance by a commercial wristband was likely because of broken sleep patterns and body movements.”

“Future sleep monitoring wearable systems could consider adding a temperature sensor to capture the waist temperature as an extra indicator of sleep combined with motion-based data and machine learning algorithms of typical sleep patterns,” they added.