A method and device (10) are provided for monitoring regular movement of the body (20) of a human subject, such as an infant. The device (10) includes electronic circuitry, an alarm and attachment means (14) for attaching to the subject's body (18), a first non-contact proximity sensor (22), and a second proximity sensor. When the device (10) is attached to the subject's body, the two proximity sensors (22,24) monitor movement of the subject's body in two sensor zones – a first sensor zone (23) and a second sensor zone (25) that is father from the device than the first sensor zone( 23). If a pattern in the distances monitored in either sensor (22,24) changes by a predetermined extent, that alarm is activated.
