Inspired by the ingestible devices that take images of the digestive tract and measure body temperature, researchers at the Massachusetts Institute of Technology (MIT) are working on a pill-sized monitoring device that tracks a patient’s heart and breathing rate. A paper discussing the technology was published in the journal PLOS One.

“In certain patient populations wearing devices for monitoring can be challenging, for example, burn and trauma patients,” Dr. Giovanni Traverso, a research affiliate at MIT’s Koch Institute for Integrative Cancer Research and one of the lead authors of the paper, told HCB News. “Also for subjects engaged in active work, such as soldiers and athletes, wearing an external sensor can be uncomfortable and result in skin irritation.”

The device can measure heart and breathing rates from certain sound waves that are produced by the beating of the heart and inhalation and exhalation of the lungs and recorded from different parts of the gastrointestinal tract.

The traditional way to measure a patient’s heart and respiratory rate is with techniques including electrocardiograms (ECG) and pulse oximetry, which require contact with a patient’s skin.

The researchers described the ingestible device as an “extremely tiny stethoscope that you can swallow.” It’s about the size of a multivitamin and consists of a small microphone inside of a silicone capsule, along with electronics that process the sound and wirelessly transmit radio signals to an external receiver.

The device will be especially useful for the military, to monitor soldiers for fatigue, dehydration, tachycardia or shock. It can also be paired with a temperature sensor to detect hypothermia, hyperthermia or fever from infections.

The researchers tested the device in the GI tract of pigs and found that it could accurately pick up heart and respiratory rates even when the amount of food being digested varies. They are currently developing the next generation device and are planning to conduct further pre-clinical testing in the next three to six months.

“Part of the next phase of development includes testing the devices in different pathophysiologic states as well as in awake and mobile subjects,” said Traverso.

In the future, the researchers are planning on creating sensors that can diagnose heart conditions like arrhythmias, emphysema and asthma. Patients have to wear a Holter monitor for a week to detect those conditions, but many times they don’t lead to a diagnosis because patients are uncomfortable wearing them 24 hours a day.

They are also planning to develop sensors that can deliver a drug to treat those conditions. They hope that one day they will be able to detect certain molecules or pathogens and then deliver antibiotics, for example.

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