Patent ID: 8664604

Claim:
A system for surveillance of a delimited area ( 2 ) within which people move, characterized in that it comprises: at least one hollow optical fibre ( 10 ) configured to extend through said area ( 2 ), said hollow optical fibre ( 10 ) being provided throughout its length with a plurality of holes ( 12 ) that set an internal channel ( 11 ) of the fibre in communication with the outside of the fibre; conveyor means ( 16 ) designed to provide a forced flow of air along said internal channel ( 11 ) of the hollow optical fibre; optical sources ( 20 ) configured for supplying said optical signal to a first end ( 10 a ) of said hollow optical fibre ( 10 ); optical sensors ( 24 ) designed to detect the optical signal present at a second end ( 10 b ) of the fibre; optical-coupling means ( 22 a ) ( 22 b ) ( 23 ) ( 25 a ) ( 25 b ) designed to guide an optical signal from the laser source to one end of the hollow optical fibre and from one end of the hollow optical fibre to the sensors ( 21 ) ( 24 ); connection interfaces ( 15 ) ( 17 ) designed to convey the optical signal and the flow of air at input to and at output from the end of the hollow optical fibre; a system for acquisition, digitalization, and processing of the signal ( 30 ) designed to examine the spectrum of the optical signal detected by said sensor means ( 24 ) in order to detect the presence of toxic agents present in the area and drawn into said internal channel ( 11 ), said system comprising a plurality of hollow optical fibres ( 10 ′, 10 ″) that extend in said area according to a grid structure.