An emergency medical device includes a power source (12) configured to power one or more subsystems of the device. A user activity detection module (56) is configured to sense user activity in the one or more subsystems, and a clinical activity detection module (54) is configured to sense clinical activity in the one or more subsystems. A control module (30) is coupled to the one or more subsystems and configured to alter a power status of the one or more subsystems in accordance with an activity sensed in at least one of the user activity detection module and the clinical activity detection module.
