專利摘要：
A motion detection method and device are introduced. The motion detection method is adapted to detect accelerations of an intended target along the x-axis, y-axis, and y-axis, respectively, and determine whether the intended target is in a fallen state or is undergoing a falling motion according to a signal strength algorithm and an average force field algorithm. The motion detection device includes an acceleration sensing unit for detecting acceleration along the x-axis, y-axis, and y-axis; a computing unit for determining a falling motion according to the acceleration along the x-axis, y-axis, and y-axis; and a transmitting unit for sending a message pertaining to the falling motion.