Smart pills to help diagnose gut disorders

The idea of journeying inside the human body to solve health problems has been around at least since science fiction popularizations, but the approach to medicine has yet to become real.

Now, researchers at Caltech have developed what they describe as GPS for smart pills, small enough to travel through the human body and help diagnose ailments. The smart pills can collect health data, record images and even deliver drugs as they pass through the gastrointestinal, or GI, tract.

To do its job well, however, a smart pill must know its location in the body. "Wireless localization of smart pills and other tiny devices deep inside the body, with high accuracy, is very challenging," says electrical engineer Azita Emami. "A low-cost solution could open new avenues in diagnosis and treatment of common medical conditions."

Chemical and biomedical engineer Mikhail Shapiro says there are three possible ways to access locations inside the body to see what is going on.

"We can place something inside like a colonoscopy device, cut the body open, or you can swallow a little pill that makes the relevant measurements," Shapiro says. "I think most people would choose the latter if it provides the performance needed to diagnose and treat them."

Caltech researcher Saransh Sharma developed the smart-pill technology with Emami and Shapiro. It was tested in collaboration with researchers at the Massachusetts Institute of Technology. A paper describing the work appears in the journal Nature Electronics. The research was supported in part by the U.S. National Science Foundation.

The technology has been dubbed iMAG, short for Ingestible Microdevices for Anatomic-mapping of Gastrointestinal-tract. It is not the first implementation of a trackable smart pill, but its creators say it is the most accurate and easiest to follow.

Emami says monitoring digestive tract motility has commonly required a patient to drink multiple "markers" then be X-rayed later to see how far the markers have moved. "That doesn't show dynamic movement, though," she says. "What we are doing shows real-time movement, and there is the possibility that we could add drug delivery or sensing to the smart pill."

Emami says previous attempts at real-time movement tracking of smart pills relied on what is known as radio frequency triangulation; the pill was essentially a radio beacon. Although RF triangulation works, it cannot pinpoint the location of a smart pill with a resolution better than a few centimeters, which is not accurate enough to pinpoint where a pill is sitting in the twists and turns of the intestines. The iMAG pill, however, has the potential to be located with submillimeter accuracy, Emami says.