PBS will profile an electronic nose created by two Tufts scientists that may become a critical tool for countries littered with leftover land mines.

Boston [10.15.01] -- Finding and removing the 110 million live land mines left in past and present combat zones around the world is extremely time consuming and dangerous work. The stakes are high and mistakes are often deadly. But two Tufts Medical School scientists are developing new technology -- in the form of an electronic nose -- that may help sniff out the explosives.

   "Tufts University neuroscientists John Kauer and Joel White introduced [PBS Scientific American Frontiers host] Alan Alda to a new machine that they hope will one day save thousands of lives," reported PBS. "These scientists have built a sniffing device modeled after a dog's nose that may help safely detect the estimated 50 to 100 million landmines buried around the world."

   On Tuesday, Oct. 16, Scientific American Frontiers will profile the pair's work in a new episode of the program entitled "Pet-Tech," which examines "the convergence of new technology and the household pet."

   The device, which has been in development for several years, can detect the odor of TNT, DNT and other explosive chemicals, helping find landmines that may otherwise have been "invisible."

   And that is invaluable to war torn countries still littered with the buried explosive devices.

   "Because they are so difficult to find, people are losing limbs and lives, and countries with economies based on farming can't rebuild after war," Tufts' John Kauer told Discover Magazine.

   Currently, workers with Kevlar suits crawl along the ground with 18-inch sticks, feeling for the buried explosives. Metal detectors aren't very reliable -- they can't detect mines encased in plastic -- and trained dogs are extremely expensive to maintain.

   But by detecting the chemical particles from the explosives in the soil and air immediately above the buried mines, the "nose" developed by Tufts' Kauer and White may provide a breakthrough.

   Using grants from the National Institutes of Health, the Office of Naval Research and the Defense Advanced Research Projects Agency, the Tufts team constructed a virtual nose that can "smell" trace amounts of chemicals in the air.

   The science powering the Tufts nose is extremely complicated.

   "Finding those scattered TNT and DNT molecules requires a daunting mix of sensitivity and selectivity," reported the September issue of Discover Magazine, which noted that some mines may only give off a few particles of explosives per trillion. "Kauer isn't quite there yet ... but he and other electronic nose pioneers are getting close."

   When PBS' Alan Alda tried the machine during the taping of the Frontiers segment in Feb. 2001, he discovered just how far the scientists have advanced.

   "In a test run with Alda, the virtual nose easily detected the difference between plain air, non-explosive DNT and methanol," reported PBS last winter. "The machine can smell odors at concentrations as low as 10-20 parts per billion, but the scientists hope to get it down to one part per billion. Then it would rival a real dog's nose, and help authorities find those millions of unexploded mines."

   Just four months after Alda's test of the device, the Tufts team made another leap forward. In June 2001, Kauer and White tested their nose against the trained noses of mine detection dogs.

   "Their device performed just as well as the dogs did under similar test conditions," reported the public television network. "Both the dog noses and the man-made nose were able to detect the chemical at concentrations below one part per billion, the goal the scientists had aimed for. Kauer and White's device had improved tenfold."

   But mine detection isn't the only field that may benefit from the Tufts nose.

   According to Discover Magazine, "The technology may soon find a host of uses: diagnosing disease, improving airport security, monitoring food safety, even enhancing your own sense of smell."

   In fact, the science magazine reported that White thinks an electronic nose may one day be incorporated into the human body.

   "White imagines a day when a supersensitive electronic nose could be wired directly into the human brain to allow us to explore the vivid world of smells currently experienced by our pets," reported Discover.

   For now, the Tufts scientists are focused on improving the sensitivity and accuracy of their machine.

   "We're still a long way from being willing to walk across an unmarked field blindly," White told PBS. "But it's definitely a step in that direction."