Measuring about the size of a vitamin tablet, the device uses an accelerometer to measure the slight movements generated by the heart beating and the lungs expanding. The capsule also contains two small batteries and a wireless antenna, enabling data to be transmitted to an external device such as a laptop or smartphone.
Although it is designed to work from the stomach, the MIT team said it can still function further along the digestive system, usually passing through a patient within 24 hours. In a study of 10 human volunteers, the device was used to monitor vital signs and detect sleep apnoea episodes where a patient repeatedly stops and starts breathing during sleep. The work is published in the journal Device.
“It’s an exciting intervention to help people be diagnosed and then receive the appropriate treatment if they suffer from obstructive sleep apnoea,” said Giovanni Traverso, an associate professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital.
“What we were able to show is that using the capsule, we could capture data that matched what the traditional transdermal sensors would capture. We also observed that the capsule could detect apnoea, and that was confirmed with standard monitoring systems that are available in the sleep lab.”
Over the past decade, Traverso and colleagues have developed a range of ingestible sensors that could be used to treat diabetes and diagnose disorders of the GI tract, such as gastrointestinal slowdown and inflammatory bowel diseases. With the latest device shown to be adept at tracking vital signs, the team believes it has the potential to play a role in tackling the opioid crisis in the US, where the number of overdoses has risen sharpy in recent years.
“We know that people who have had an overdose are at higher risk of recurrence, so those individuals could be monitored more closely so that in the event of another overdose, someone could help them,” Traverso said.
“The device also has the potential for early detection of changes in respiratory status, whether it’s a result of opiates or other conditions that could be monitored, like asthma or chronic obstructive pulmonary disease (COPD).”
Future plans include incorporating an overdose reversal agent such as nalmefene into the device, whereby drug release could be triggered when a person’s breathing rate slowed or stopped. The team is also working on strategies to lengthen the amount of time that the capsules can remain in the stomach.