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A snake in your guts!

FEELING poorly? You might get to know what is wrong deep inside you by swallowing a snake- a robotic snake, that is -designed to wind its way through your intestines and photograph any abnormality there by its miniature video cameras. If it is a robot that slithers or wriggles or creeps, then the California Institute of Technology, us, has had something to do with it. For years, Caltech researchers have built and modified malleable robots based on nature. Some of the earlier models, like the centipede, the worm and the slug ultimately paved the way for the Robosnake. Says I J oel, leader of the Caltech research team, "It can crawl into places where conventional robots can't reach." The models are different in structure and function -some crawl fast, some are slow and stable; some are for fluid, slippery surfaces, while others are for those with high friction.

Joel and his team started their work on 'bending robots' as it seemed a niche idea, without any possible use in mind at the outset. Robosnake, however, was built for a very specific purpose. It was designed to explore the human gut. The tubular snake is made of two different components. These are two flexible concentric tubes. The outer transparent cover is equipped with inflatable pockets that can swell up and thus grip the intestinal walls from inside. The inner tube has got stretching segments and these are responsible for pushing the snake backward and forward. The inner tube is also lined with miniature video cameras that can be remotely con- trolled for aperture and focus. The snake has a tiny transmitter embedded at one end that can send the digitised images of the intestinal snapshots. Like an endoscope, the snake is inserted through the throat and placed at the start of the gut, from where "it sets off on its own steam".

The Robosnake has been tested in simulated environs of an artificial intestine. The projected uses for this device would looking for cancerous tumours, but it would also be able to take simple biopsy samples. Another application could be unlocking of intestinal block- ages.

Though it sounds feasible enough, the question remains whether patients would agree to have an 'inanimate' creature crawling through their intestines. "Initially, the idea seems weird, even creepyat times," says Joel, "but the only alternative is to go under a surgeon's knife, recovering after a couple of months and living with a five-inch scar on the stomach."

Robosnake, however, would be tried on a real patient only after the team figures out what to do if it gets stuck. None of the suggestions, unfortunately, sound very pleasant, to say the least. The snake can be ordered to 'self-destruct' and the small pieces would ultimately be flushed with the natural end-products of the digestive system. The possibility of a small parts persisting in the body, how- ever, remains. Another idea is to attach a fine steel cable to the snake and drag it out when required. Patients, no doubt, would not like that either. Joel's futuristic idea has not yet been lapped by any major multinational pharmaceutical firm. But he has already embarked on a project to build mini-Robosnakes, which will wriggle their ways through veins and arteries. That would be some- thing surely worth the wait.