In the realm of medical technology, a novel electronic pill is making waves with its ability to transmit Wi-Fi signals from within the human body. This innovative device, powered by the stomach's own acidic environment, can continuously send updates about core body temperature to an external monitor for several days. This marks a significant advancement over existing ingestible devices, which typically have a much shorter operational lifespan.
While this pill won't allow for direct communication like phone calls, its potential applications in healthcare are vast. Giovanni Traverso, a gastroenterologist and biomedical engineer at Brigham and Women's Hospital in Boston, highlights its promise for revolutionizing drug delivery systems and enabling real-time health monitoring from inside the body.
Accurate measurement of core body temperature is crucial in medical settings, yet it remains a challenge. Traditional methods, such as oral or skin thermometers, often fail to provide precise readings. This can pose significant risks, particularly for patients under anesthesia or those susceptible to infections. A recent study involving thousands of patients underscored the need for more reliable temperature monitoring solutions.
Traverso, who has previously developed innovative ingestible devices for drug delivery, began exploring the concept of integrating a power source into these devices a few years ago. The idea was inspired by the simple yet effective lemon battery experiment, where zinc and copper electrodes in an acidic environment generate electricity.
In this new pill, miniaturized copper and zinc electrodes react with stomach acid to produce electrons, creating a small but steady power source. Philip Nadeau, an electrical engineer and co-designer of the device, explains that this setup allows the pill to harvest energy efficiently.
Harnessing Stomach Power
The pill's electrodes are mounted on a silicon capsule that houses the necessary circuits and electronics. Although the initial power output from the stomach's acidic juices is modest, engineers have incorporated an energy storage capacitor to amplify the voltage to usable levels. This setup generates power comparable to that of many Bluetooth devices.
To test the device, Nadeau and his team conducted experiments on pigs. Each pill was equipped with electrodes, a temperature sensor, and a Wi-Fi transmitter capable of sending data to a receiver up to 32 feet away. The device successfully transmitted temperature readings and system performance data every 12 seconds.
Over a six-day period, the pill monitored core body temperature as it traveled through the pigs' digestive systems. This duration far exceeds the capabilities of previous devices, which could only function for a short time. Another version of the prototype demonstrated the potential for using harvested energy to administer medication.
Future Developments and Safety
John Rogers, a physical chemist at the University of Illinois at Urbana-Champaign, commended the achievement, noting the sustained power levels over several days. The pill's design ensures that only the zinc and copper electrodes are exposed to the stomach environment, while the rest of the electronics are safely encased in silicone. The zinc released is comparable to typical dietary supplements, but further studies are needed to assess the safety of copper exposure before human trials can proceed.
Looking ahead, Traverso and Nadeau are exploring the use of more biocompatible materials to replace copper and are working on reducing the pill's size to make it more palatable for ingestion. The goal is to create a device that is as easy to swallow as a standard tablet.
Beyond temperature monitoring, Traverso envisions a future where such devices could track a range of vital signs, including heart and respiratory rates. This could pave the way for diagnosing and managing respiratory and cardiovascular conditions over extended periods, offering a new frontier in personalized healthcare.