An electronic sensor can measure your heart rate and breathing rate from within your gastrointestinal tract, say MIT scientists… but first you must swallow. The ingestible sensor calculates heart and breathing rates from distinctive sound waves produced by the body in its actions, a process described in the published research.

Someday, the new sensor could become a doctor’s go-to method for measuring vital signs and performing long-term evaluation of patients with chronic illnesses, athletes, trauma patients, or soldiers in battle. 

Tested in pigs, the prototype is, according to the researchers, superior to currently used technologies such as electrocardiograms (ECG) and pulse oximetry, which require contact with a patient’s skin and so may impact the results (or simply cause irritation). Sometimes doctors will try wearable monitors instead, but patients often complain they are uncomfortable to wear. The research team set out to design a new sensor, one that would measure heart and respiratory rates plus body temperature from inside the digestive tract.

Inspired by other technologies both old (stethoscope) and new (the current wave of ingestible devices), the research team decided to achieve their goal by listening to the body using a small microphone. As they see it, they needed to create a very tiny stethoscope that would go down in one gulp. The advantage to such a sensor would be it might collect both heart sounds and lung sounds, two vital pieces of information, at once.

The sensor is about the size of a multivitamin and consists of a tiny microphone packaged inside a silicone capsule. Also included in this "pill" are electronics able to process sound and wirelessly send radio signals to an external receiver, within a range of about 3 meters. One difficulty faced by the team, led by Gregory Ciccarelli, MIT’s Lincoln Laboratory, and Giovanni Traverso, MIT’s Koch Institute for Integrative Cancer Research, was translating all the acoustic data received.

Not only did the team need to devise signal processing systems that could distinguish the sounds produced by the heart and lungs, but they also had to filter out any background noise produced by other body parts and also when a patient is eating.

The researchers say the device would remain in a patient’s digestive tract for only a day or two, so any longer-term monitoring would require new capsules, swallowed as needed. Watch the video below, courtesy of MIT, to see for yourself:

Source: Traverso G, Ciccarelli G, Schwartz S, et al. Physiologic Status Monitoring via the Gastrointestinal Tract. PLOS ONE. 2015.