Analysis of vibration and comfort in infants.

Infants are routinely subjected to vibration and stress when moved. While some research exists for simulated motion in cars, other transportation means such as prams are rarely studied. Additionally, the effect of vibration on the comfort of infants or young children who are unable to provide feedback has never been addressed. The objective of this study was to measure and evaluate vibrations transmitted to infants lying on a pram during a walk using wearable inertial measurement units. Sensors were placed on the infant's forehead and thorax, on the pram, on the ankle and wrist of the parent pushing the pram on four types of terrain, and specifically resin floor, asphalt, porphyry, and gravel. The amount of vibrations transmitted to the infants was assessed by comparing the acceleration measured near the pram wheels with that measured on the infants' thorax. The comfort level of the child was measured using the COMFORTneo scale, i.e., a method used by clinicians to measure neonates' comfort and distress levels. The cradle and mattress act as a low-pass filter attenuating vibrations measured near the pram wheel as a result of moving on different terrains. On the terrains tested, the median value of acceleration measured at the infants' thorax did not exceed the ISO guidelines for vibration levels perceived as hazardous to human health by an adult. This research demonstrates the feasibility of measuring vibrations on infants during transport and provides insights on vibration exposure on different types of terrain.