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Dartmouth Medical School Dartmouth-Hitchcock Medical Center


A somersaulting, picture-taking pill

By Matthew C. Wiencke

The new maneuverable wireless capsule is just about the size of a quarter.

Imagine swallowing a capsule that's like a Swiss Army knife, says DHMC gastroenterologist Richard Rothstein, M.D. It could have a tiny forceps that would open up and snip off tissue for a biopsy, or maybe a little laser wand or a heat probe.

Such a device doesn't exist quite yet, but a step in that direction came with a study Rothstein led at DHMC—the first use in a human of a wireless capsule externally controlled by magnets. The hope is that it will improve the diagnosis of gastrointestinal (GI) problems.

Wireless capsules have long been used to examine the GI tract, but most go straight through the body, snapping photos without stopping. Rothstein and his collaborators—including Paul Swain, M.D., of London's Imperial College, the inventor of the wireless capsule—took a different approach. They started with a capsule that has a camera capable of transmitting four images per second to real-time video. Then they added a stack of magnets to the capsule.

Wireless wonder

Watch the wireless capsule at work.
Watch video

Magnet: After a volunteer (Swain) swallowed the capsule, Rothstein maneuvered a handheld magnet across Swain's body to guide the capsule around inside him. Another researcher inserted a video-gastroscope into Swain's esophagus so the team could study the coordination of the handheld magnet with the capsule's movements.

For the most part, the researchers found it quite easy to manipulate the capsule. They moved it up to the cardia (where the esophagus opens into the stomach), held it in place against gravity, and then let it drop to a lower part of the stomach. Rotations and somersaults were also possible, allowing the capsule to take images of the cardia from many different angles. Pulling the capsule up and down the esophagus and stopping its motion there was more difficult, since the distance between the inner and outer magnets was greater, but rotating it in the esophagus worked well. The results of the study were published in Gastrointestinal Endoscopy.

Thanks to its unique maneuverability, says Rothstein, the new capsule promises to help locate a bleeding site or diagnose Crohn's disease, for example. "Eventually we'll be able to take full biopsies by having . . . a little guillotine-like biopsy port on a capsule," he says. "We're only limited by our imagination."

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