Patent EP-2056092-A1 (EP)
Inventor: IVANOV ALEKSEI VALENTINOVICH
IPC: G01N33/18
Filed: 2007-06-15
Abstract: The invention relates to the field of environment conservation, in particular, to methods and means of ecological environment monitoring with the help of a non-invasive control of functional state of native animals. The invention can predominantly be used for automatic on-line estimation of environment quality on the basis of remote real-time registration of cardiac activity in invertebrates with a hard outer covering. 
     The method includes placing the test invertebrate in the environment under investigation, exposing it to IR optical radiation with the help of a transmitting optical fibre with the output end placed on its hard outer covering within its heart area and an optical radiation source being in optical contact with the input end of the transmitting optical fibre; receiving the reflected optical radiation with the help of the receiving optical fibre with its input end placed on the test invertebrate's hard outer covering within its heart area; converting it to an electrical signal with the help of the optical radiation receiver being in optical contact with the output end of the receiving optical fibre; amplifying the signal obtained; converting its instantaneous values to digital codes; entering them to the computer; making digital filtration of digital codes which is matched to the signal's shape and frequency; determining and memorizing the sample of values of the electrical signal period; determining a sample dispersion or arithmetical mean of difference moduli for each two, closest by the time of obtaining, sample values of the electrical signal period; and forming an ecological danger signal when the threshold value exceeds the sample dispersion of values of the electrical signal period or arithmetical mean of difference moduli for each two, closest by the time of obtaining, sample values of the electrical signal period. 
     The system contains a computer and at least one shaper of the digital signal of cardiac activity in the form of series-connected cardiac activity sensor including a casing with an element for installing on the test invertebrate's body with a hard outer covering, a transmitting optical fibre and receiving optical fibre, an optical radiation source and optical radiation receiver; an amplifier and analog-to-digital converter whose output is connected to the computer input. The input end of the transmitting optical fibre and output end of the receiving optical fibre are secured so that they can have optical contact with, respectively, the optical radiation source and optical radiation receiver, and the output end of the transmitting optical fibre and input end of the receiving optical fibre face one side and are positioned in the casing at a distance satisfying the inequality          π         d   2     ⁢   P       0   ,   07       -   2   ,   2   ⁢       1   /     π         d   2     ⁢   P         0   ,   02       ≤   R   ≤       π         d   2     ⁢   P       0   ,   07       +   2   ,   2   ⁢       1   /     π         d   2     ⁢   P         0   ,   02       ,         
where  R  - distance between the output end of the transmitting optical fibre and input end of the receiving optical fibre, mm;  P  - output power of the optical radiation source, mW;  d  - diameter of the transmitting optical fibre or receiving optical fibre, µm. 
     The invention provides a higher reliability of environment monitoring, widening of functional potentials, as well as lower cost and simpler operation of the system for biological environment monitoring.