Automated external defibrillators with automatic selection between adult and paediatric defibrillation doses

Described is an automated external defibrillator (AED) and method of use, the AED comprising two pads to be placed on a patient, each pad comprising at least one electrode, an angular motion sensor, and a shock generation circuit configured to generate a dose of defibrillation shock, and wherein at least one pad comprises a processor with memory and power supply, wherein the processor is configured to analyse an angular motion signal from each of the two angular motion sensors to determine an orientation of the two pads relative to one another, analyse electrocardiogram (ECG) signals from the two electrodes to determine shockable cardiac rhythms, and automatically select between an adult dose and an infant dose of defibrillation shock to be delivered by the two electrodes based, at least in part, on the relative orientation of the two pads.