Physiology of everyday sleep and physical activity: An exploratory mixed-methods study of multi-sensor wearables for infants and toddlers.

Seven children aged 4-36 months completed the study, recruited from playgroups and social networks in the North East of England.

• A longitudinal within-case design was employed.
• Children were aged 4-36 months.
• Families were recruited through playgroups and social networks.
• Parents and children tested two wearable devices in a structured play setting and at home over a period of 1 week.

The Bittium Faros 180 heart rate monitor was considered uncomfortable, its large size hindered activity, and electrode detachment by parents and accidentally led to significant data loss.

• The device was assessed through researcher observations and parent feedback using ethnographic methods.
• Electrode detachment occurred both accidentally and was performed by parents intentionally.
• Large device size was identified as a hindrance to children's physical activity.
• Significant data loss resulted from electrode detachment issues.

The NAPPA sleep monitoring system was easier to use, discreet, and comfortable compared to the heart rate monitor, but it disrupted sleep routines.

• Usability was assessed through researcher observations and parent feedback.
• NAPPA was described as 'discreet' and 'comfortable' by parents.
• Despite better wearability, the NAPPA disrupted children's sleep routines.
• Both devices were evaluated across a 1-week home use period.

Non-parental caregiving contexts resulted in non-wear and/or data loss, representing an additional usability challenge.

• Non-parental caregivers were identified as a source of study protocol non-compliance.
• This challenge contributed to overall data loss across the study.
• The finding highlights a practical barrier to large-scale longitudinal monitoring in young children.

Data on wear time, heart rate variability during naps, and ultradian respiration cycles during sleep were analysed from the wearable sensors.

• The Bittium Faros 180 heart rate monitor and the NAPPA sleep monitoring system were used for data collection.
• Physiological measurements included sleep, movement, and heart rate.
• Heart rate variability during naps was a specific outcome measure.
• Ultradian respiration cycles during sleep were also analysed.

Parents were initially enthusiastic about the wearable devices but usability challenges arose during the study period.

• Initial parental enthusiasm was documented through ethnographic methods.
• Usability challenges emerged over the course of the 1-week testing period.
• Challenges spanned both the structured play setting and home environment.
• The mixed-methods approach combined physiological data collection with researcher observations and parent feedback.

Co-creation of child-friendly, practical hardware and software is identified as essential for effective large-scale health monitoring in young children.

• The study was described as hypothesis-generating.
• Results indicated wearable devices hold potential but face significant design challenges for longitudinal home use at scale.
• Co-creation was recommended as an approach to address both hardware and software limitations.
• The findings are intended to inform future development of wearable monitoring tools for infants and toddlers.