Electronic pills have been used for diagnostic applications such as imaging, but the iPill from Philips Research, designed to treat gastrointestinal disorders, goes a step further, dispensing medication at a location and rate programmed by a physician. The disposable capsule, which is about the same size as an ordinary pill, contains a tiny computer, a wireless transmitter, and a series of sensors; it passes naturally through the digestive system after being swallowed with food or water. Although the iPill is still a prototype, Philips is about to begin testing it in animals and is working with pharmaceutical companies to evaluate what drugs might work best with it.

A. Microprocessor
Before the iPill is swallowed, a doctor loads it with a program that instructs it where to deliver its contents. The microprocessor monitors the pill's location, using data on pH, temperature, and the time elapsed since ingestion, and then determines when and in what pattern the pill's fluid pump will release drugs into the patient's digestive tract.