Dozer: Towards understanding the design of closed-loop wearables for sleep

Sleep plays a paramount role in maintaining healthy bodily functioning. Yet, poor sleep is an increasingly prevalent global health concern. Most current sleep technology tracks sleep, but how to design for promoting sleep is relatively underexplored. We highlight the potential of employing closed-loop systems for promoting sleep onset and explore this through the design and study of “Dozer”, a closed-loop beanie that accelerates sleep onset through auditory and electrical brain stimulation after detecting drowsiness in EEG. In an in-the-wild study, participant interviews revealed three UX themes (closed-loop neurocentric agency, awareness of hardware, and awareness of feedback), which ultimately suggested that participants fell asleep in spite of Dozer, rather than through its assistance. We interpret these results and provide actionable design tactics to inform the design of closed-loop sleep systems moving forward. We hope this work gives rise to a deeper understanding of designing closed techno-physiological loops.