Swallowing electronics is not usually recommended. But researchers in Belgium and the Netherlands have worked out how to make eating components, from a wireless transmitter and microchips to a battery and a suite of chemical sensors, not just safe but useful.
The result is gismo (gastrointestinal smart module): an edible capsule about the size of a Tic Tac that travels the length of the human gut, takes a chemical reading every 20 seconds and sends the results to a receiver worn on the belt. It is an early example of a new generation of ingestible devices that can report back, live, from inside the gut. Potential applications run from routine diagnosis to targeted drug delivery, and eventually to electronics made entirely from food.
The gismo measures changes in the gut’s “redox balance”, which can offer an early warning of inflamed or diseased tissue. Researchers are now testing it in people with ulcerative colitis and colorectal cancer. Patients swallow it before breakfast and must recover it, in the usual way, a few days later.
The human gut is an enormously complex ecosystem, home to trillions of microorganisms whose collective metabolic output offers a running commentary on their host’s health. It has usually been difficult territory for doctors—endoscopy and colonoscopy can examine parts of it directly, but they are invasive. A standard colonoscopy takes around 30 minutes, costs several hundred pounds, and is unpleasant enough that many patients who need one simply avoid it.
A swallowable camera called PillCam solved the visual part of that problem more than two decades ago. According to Medtronic, a firm based in Minneapolis which now owns the technology, PillCam has been used in more than four million patients worldwide. But the most important signals in the gut are often environmental: gases produced by microbes, acidity, the outputs of chemical reactions, inflammatory molecules, and how those conditions change with food, disease and drugs.
Full Story: Tomorrow’s medical sensors might come served with dinner (The Economist)