Just a few weeks ago news emerged of edible batteries that could aid in smart medicine. But it seems that ingestible technology has been around since the '80s.

The U.S. military have been using an ingestible thermometer pill for 25 years, to monitor the core body temperature of service members during physically demanding missions. The CorTemp pill was developed in the mid-1980s by the Johns Hopkins Applied Physics Laboratory and the Goddard Space Flight Center.

Its sensor technology was first used on astronauts to detect hypothermia and hyperthermic conditions during space flight.

Soldiers swallow a 3/4-inch silicone-coated capsule that contains a microbattery and a quartz crystal temperature sensor. Within two hours, the quartz crystal sensor vibrates at a frequency relative to the body's temperature and transmits a harmless, low-frequency signal through the body.


Image from CorTemp (HQ, Inc.)

Team personnel wirelessly monitor the core body temperature of multiple subjects in real time. There are several options and configurations for tracking temperatures, including the most simple method of holding the data recorder near the small of the back. But unlike those biodegradeble edible batteries of the future, this pill safely passes through the digestive system after 18 to 30 hours.

At $50 per pill, it's used at the Special Warfare Combatant-craft Crewmen (SWCC) training facility in Coronado, Calif. where candidates swim in open sea ranging from 48 degrees Fahrenheit to 72 degrees Farenheit.

"For SWCC personnel, the pill is used to monitor body core temperature and is used only in training. Its use ensures candidates can understand the impact of cold water and allows medical and training cadre staff to ensure safety parameters for training are observed," wrote Navy Lt. Ben Tisdale via email.

According to Director of Sales & Marketing, Lee Carbonelli, these ingestible capsules are also used by the NFL, European militaries, and fire departments in the United States and in Australia.