A decade ago it seemed unlikely that an individual’s temperature, heart rate and breathing could be constantly measured by a device encapsulated in a thin, delicate rubber band, but in 2017 Fitbits and Apple Watches are almost as common as cellphones. However, if newly published research is headed in the right direction, external health-monitoring devices will soon be obsolete. They’ll be replaced with internal, ingestible devices.
These ingestible, self-powered capsules could monitor vitals for weeks, transmitting the measurements to a cellphone so you can stay 100 percent up to date with everything your body is doing. The devices could also be used to deliver drugs, especially in the case of the dose size of certain blood pressure-controlling drugs that doctors need to tailor to how an individual’s body reacts.
The idea of these ingestible health trackers were originally inspired by the concept of the lemon battery — a common elementary school project in which an actual battery is made by sticking pieces of zinc and copper into a lemon. Researchers at MIT and Brigham and Women’s Hospital took that concept and found they could create a battery with stomach acid (in lieu of fruit) and a small sensor with zinc and copper electrodes on the outside. Meaning your body actually acts as the tracker’s battery.
While these devices are currently being tested out on pigs, it’s likely they will make their way into humans soon enough because studies are going quite well. When the swine swallow the devices, electrodes react with their stomach acid and produce enough electricity to power a temperature sensor. In addition, it powers a wireless transmitter that broadcasts the data every 12 seconds for an average of six days before the device passes through their bodies.
“I think it really opens up different possibilities for ways of powering long-term resident systems in the body,” says Giovanni Traverso, a lead author of the study. He and fellow researcher Robert Langer point out that most ingestible electronic devices are powered by small batteries, which become safety risks because of the simple fact that they self-discharge over time. This motivated them to look into the option of using the body to create energy.
To get started, they had the pigs swallow a device to measure how much electricity could be produced in the stomach and intestines. They then designed their prototype capsule accordingly: around 40 millimeters long and 12 millimeters in diameter. Eventually they think the capsule can be reduced to one-third the size, which would likely enable them to add other types of sensors and develop it for such applications as long-term monitoring of vital signs.
“This work could lead to a new generation of electronic ingestible pills that could someday enable novel ways of monitoring patient health and/or treating disease,” Langer explains.
Scientists not involved in the study concur. “This paper reports an exciting and remarkably broad collection of advances in ‘ingestible’ electronics — from bioresorbable power supplies to energy-efficient electronics, advanced sensors/actuators and wireless communication systems,” John Rogers, a professor of materials science and engineering at Northwestern University who was not involved in the research, says. “These types of systems have great potential to address important clinical needs.”
Don’t throw away your Fitbit or Apple Watch quite yet! It will be at least three to five years before the devices are tested on human subjects, according to Traverso. But if research keeps heading in the right direction, you just may be swallowing you health-monitoring devices in the 2020s.
What Do YOU Think?
Do you think ingestible health-monitoring devices will be a thing of the future? Would you feel comfortable swallowing one? Do you think these systems will revolutionize the medical industry?