Abstract: An alarm device for monitoring the movements of a person is disclosed. The device is designed to be attached to a person's clothing and is particularly suitable for use by an emergency worker, such as a fireman. The device comprises a motion sensor, a signal processing circuit on a printed circuit board, and an alarm, all contained within a housing. The motion sensor includes a permanent magnet attached to one end of a spring located within an induction coil wound on a bobbin. The other end of the spring is attached to the printed circuit board so that a voltage is induced across the coil due to vibrations of the magnet relative to the coil in response to movements of the housing of the device. The signal processing circuit activates the alarm to generate an alarm signal if the person is immobile, for example, as the result of an injury, for a predetermined period of time.