Fig 1.
Opal sensors worn on an infant.
(A) A wearable sensor used in each recording. (B) Custom-made legwarmers with sensors inserted put on each ankle of an infant.
Fig 2.
Flow diagram of subject participation in a study of wearable sensors to assess leg movement in infants in rural Guatemala.
Table 1.
Baseline characteristics of participants (N = 41).
Fig 3.
Age dependent change of the movement characteristics.
(A) Leg movement rate, (B) left leg peak acceleration per movement, and (C) right leg peak acceleration per movement are plotted against age at each recording. Age is in days since birth. Connected gray dots are estimated hours of infant swaddling reported for each infant across three visits. Thick black lines are linear estimation of the age dependent trends. Shading around the lines indicate 95% confidence intervals.
Table 2.
Growth and movement characteristics of infants per visit.
Table 3.
Estimated hours of infant swaddling at each study visit.
Fig 4.
Age dependent change in hours of infant swaddling.
The top row shows caregiver estimated hours infants were swaddled (A) in total, (B) laid down on the floor, or (C) against caregivers during a visit (sensors on). The bottom row displays analogous measure (D) in total, (B) when swaddled and laid down, and (C) when swaddled against caregivers. Total swaddle time is the sum of time swaddled and laid down and time swaddled against caregivers. Thick black curves are LOESS (locally estimated scatterplot smoothing) curves fitted to data to estimate age-associated change of swaddling hours. Shading around the curves indicate 95% confidence intervals.
Table 4.
Summary of models on leg movement rates.
Table 5.
Summary of models on peak acceleration per movement.
Fig 5.
Two types of time infants were swaddled against sleep time estimated by the algorithm at each visit.
Plots A-C show time swaddled and laid down against sleep time (periods of inactivity) at visit 1, 2, and 3. Plots D-F show time swaddled against caregivers against sleep time at visit 1, 2, and 3 respectively.