ananyo writes "Digestible microchips embedded in drugs may soon tell doctors whether a patient is taking their medications as prescribed. The 'digital pills' are the first ingestible devices approved by the U.S. Food and Drug Administration. The pills contain a sand-particle sized sensor, consisting of a minute silicon chip containing trace amounts of magnesium and copper. When swallowed, it generates a slight voltage in response to digestive juices, which conveys a signal to the surface of a person's skin where a patch then relays the information to a mobile phone belonging to a healthcare-provider. Currently, the FDA, and the analogous regulatory agency in Europe have only approved the device based on studies showing its safety and efficacy when implanted in placebo pills. But Proteus Digital Health, the manufacturer, hopes to have the device approved within other drugs in the near future."