Ingestible Sensor Measures Heart and Breathing Rates from Within Digestive Tract

Using technology invented at MIT, doctors may one day be able to monitor patients' vital signs by having them swallow an ingestible electronic device that measures heart rate and breathing rate from within the gastrointestinal tract. This type of sensor could make it easier to assess trauma patients, monitor soldiers in battle, and perform long-term evaluation of patients with chronic illnesses. For the military, this kind of ingestible device could be useful for monitoring soldiers for fatigue, dehydration, tachycardia, or shock. When combined with a temperature sensor, it could also detect hypothermia, hyperthermia, or fever from infections. The new sensor calculates heart and breathing rates from the distinctive sound waves produced by the beating of the heart and the inhalation and exhalation of the lungs. Through characterization of the acoustic wave, recorded from different parts of the GI tract, the MIT researchers found that they could measure both heart rate and respiratory rate with good accuracy. The entire sensor is about the size of a multivitamin pill and consists of a tiny microphone packaged in a silicone capsule, along with electronics that process the sound and wirelessly send radio signals to an external receiver, with a range of about 3 meters.

Transcript

00:00:05 The capability we're trying to develop is a way to measure your vital signs, things like heart rate, breathing rate and core temperature, in a device that you can swallow and just forget about. So what we did with our technology is identify components that were compatible with ingestion. These are very

00:00:23 small microphones, similar to the ones used in common cell phones, and actually listen from within the body and extract the heart rate and respiratory rate. The way that vital signs are collected now is almost always using a device that touches the skin. And in some cases that's

00:00:41 inconvenient, say a trauma patient, with burns that cover the majority of their body, it is impossible or extremely difficult in that case without causing a lot of pain to be touching that patient. And so we wanted to develop a capability that involved no contact with the body other

00:00:57 than within the GI tract. So the way that this is done now is you go to the doctor and they use a stethoscope to listen to your heart and lungs. We just reduce that down to the size of say an almond, and that can be easily swallowed and a device can be built around that that can wirelessly transmit the

00:01:12 data outside of the body. So I think it is important to understand that the vital signs monitoring field has been around for a while. And in fact stethoscopes have been used for over a hundred years, and are broadly used, but what really hasn't been done is actually evaluate the vital signs from

00:01:30 all the different portions of the GI tract and in all of these fed and fasting states really sort of demonstrating for the first time the capacity to do this from within. So up to now we focused on building a sensor that's small enough that you can swallow and to develop a signal processing algorithm that can

00:01:47 turn body sounds into heart and breathing rates. The next step and what we're currently working on is to build an entirely wireless device comprised only of FDA approved components that can be ingested, and we'll be testing these devices to collect heart, breathing rate and core temperature.