"Flapping Its Tailfin," the New Capsule Features Multidirectional Movement
"As a researcher working on ultra-small-sized medical devices, it occurred to me that using something like a fish's tailfin would allow a capsule to move freely within the patient's digestive system," says Professor Otsuka.
Professor Otsuka's idea of using a fin to propel the capsule eventually bore fruit when he completed the first prototype of his self-propelling capsule endoscope.
But how exactly does it move? The fin on the capsule has a permanent magnet attached to it. Once the patient has swallowed the capsule, he or she is placed into a magnetic field generator that has four large electromagnets. The magnetic fields vibrate the permanent magnet, which moves the capsule's fin. The speed and direction of the capsule can be controlled outside the body using a special control stick.
The self-propelling capsule endoscope "swims" by flapping its fin in exactly the same way a fish does.
A diagram showing a doctor examining a patient using a self-propelling capsule endoscope. When the doctor moves the control stick, the fin on the endoscope moves.
Video imaging taken by a self-propelling capsule endoscope displays the inside of the stomach on a monitor.
A patient lying within a magnetic field generator while the self-propelling capsule endoscope examines his digestive system
Before the self-propelling capsule can be used, the patient must make sure his or her digestive system is clear and then drink water or some other liquid. When the large intestine is to be examined, the water is injected via the anal canal. These preparations are necessary to create an environment in which the capsule can easily "swim." Once this situation has been created, the capsule can move freely inside the stomach and intestines, providing video imaging everywhere it goes, and the examination can be completed in several hours.
A diagram showing the self-propelling capsule endoscope "swimming" through the digestive system
Once use of the self-propelling capsule endoscope becomes widespread, doctors will be able to more easily discover most diseases of the digestive system, including Crone's disease, which is very difficult to diagnose, and cancer. "In the future," says Professor Otsuka, "new and improved versions of the capsule endoscope will be able not only to facilitate examinations, but also to surgically remove polyps, deliver medication to the disease site and perform other forms of treatment."
It seems that the dark world inside the human body is once again being illuminated by revolutionary Japanese medical technology.
(Updated in November 2011)