Leo Study Unstable Asthma

After consent and enrollment, the child's respiratory impedance will be continuously recorded using the Leo device throughout the day and night during the entire hospital stay or ED visit. The device may be taken off for up to 1 hour per day (i.e., break during bath / shower time). The device will be applied to the skin overlying the mid-sternum area on the chest wall after cleaning of the skin with an alcohol swab after consent has been obtained. The device will be changed every 72 hours or earlier, by the participant's guardian, depending on signs of defect in the signal quality or battery exhaustion, based on daily check of the signal by the research team. Remote monitoring of the child's chest impedance will continue using the Leo device after discharge from hospital/ED for 7 days.