MONITORING VITAL SIGNS

A vital signs monitor for attachment to a human or animal thorax, the monitor having a low power mode and a high accuracy mode and comprising: a motion sensor configured to, in the low power mode, sample movement at a first frequency and, in the high accuracy mode, sample movement at a second frequency, the second frequency being greater than the first frequency; and a processor configured to, in the low power mode, process a series of the one or more movement samples captured by the motion sensor in the low power mode so as to form a measure of activity level, and to, in the high accuracy mode, cause a series of the movement samples captured by the motion sensor in the high accuracy mode to be stored at the vital signs monitor and/or transmitted by means of a transceiver; wherein the processor is configured to prevent the vital signs monitor entering the high accuracy mode from the low power mode when the activity level exceeds a first predefined or dynamic threshold.