Method and device for fall detection and a system comprising such device

A method and a device for fall detection to be used in a health monitoring system in an in-house room environment are provided. The device comprises: - a PIR detection unit (10), having a given field of view, and mounted on a vertical surface, and comprising - a dual element PIR sensor (12, 14), - an infrared lens placed in front of the PIR sensor (12, 14) and dividing a plane orthogonal to its axis of symmetry into a plurality of zones in the given field of view. Each zone comprises two different sectors. The infrared lens is a Fresnel lens array (11, 13) having an optical focusing effect in a direction parallel with the axis of symmetry of the corresponding dual element PIR sensor (12, 14), which have orthogonal axis of symmetry. Output signals of both PIR sensors (12, 14) are forwarded to a signal processing MCU for evaluation of a phase of the output signals of the dual element PIR sensors (12, 14) and producing a fall detection alert signal in response to evaluation by the signal processing MCU.