Patent link: <A HREF="http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=6,344,818.WKU.&OS=PN/6,344,818&RS=PN/6,344,818" target="_blank">http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/neta...</A> also here is copy of tests of Sniffex device published on sniffex.com website recently <A HREF="http://www.sniffex.com/excerpts_from_emrtc.pdf" target="_blank">http://www.sniffex.com/excerpts_from_emrtc.pdf</A>