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.
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.
B. pH Sensor
The pH sensor helps the pill track its passage from the highly acidic stomach to the less acidic intestines. The pill’s environment grows progressively more alkaline until it reaches the colon, which is more acidic again.
C. Temperature Sensor
When the patient swallows the iPill, the temperature sensor detects the change from room temperature to body temperature. That causes the microprocessor to start the clock that will help the pill calculate its location.
D. Fluid Pump
The drugs stored in the pill’s reservoir can be released in a single burst, in a series of doses at multiple locations, or little by little as the capsule travels through the gut. The pump that releases the drugs consists of a motor and a piston driven by a screw rod, which can move precise amounts of fluid at the command of the microprocessor.
E. Wireless Transceiver
The iPill can communicate by radio frequency with a control device outside the body. It can gather temperature data, for example, and report on changes it finds as it travels. If a drug is causing a bad reaction, a doctor can send a command to stop the pill from releasing any more of it.
The iPill is powered by a silver oxide battery that holds a charge intended to last 48 hours–about twice the duration of the pill’s natural transit through the body.
Image courtesy of Philips