MIT scientists have developed a proof-of concept sensor that provides real-time heart and respiratory vital sign information internally from the gastrointestinal tract
Vital signs such as heart rate and respiratory rate are measured using methods such as electrocardiogram, pulse oximetry, and expired gas analysis. These methods, while common, are limited, as they may irritate the skin or are unpractical in situations of high physical activity. An MIT-based research group recently reported in PLoS One that they had developed an ingestible sensor and completed critical proof-of concept physiological monitoring experiments using a pig model to measure heart and respiratory rates simultaneously from the gastrointestinal (GI) tract.
The sensor is approximately the size of a small capsule and when ingested, was able to collect raw heart and lung sound information in the GI tract which was then isolated into their respective components using a processing algorithm. The vital signs of the pigs were concurrently recorded using standard veterinary monitors, and the sensor successfully recorded sounds at comparable resolution. The ingestible sensor was also tested in states when the GI tract was full of solid, liquid and gas content, as well as in contact with the gastric wall. In all cases, the sensor was successful in recording physiological information with a small amount of error.
The further development of ingestible electronics, in particular a sensor that can measure vital signs simultaneously, would be extremely useful in both clinical and non-clinical situations, such as in the diagnosis of abnormal conditions like arrhythmias, emergency medicine, telemedicine, and in military service. The sensor can remain in the body for up to two days depending on the health of the individual, so at present can only provide short-term information. Future experimentation with this ingestible sensor will likely examine its limitations in a noisy environment and under conditions of physical activity, as well as in human subjects.
Traverso G, Ciccarelli G, Schwartz S, Hughes T, Boettcher T, Barman R, et al. Physiologic Status Monitoring via the Gastrointestinal Tract. PLoS ONE 10(11): e0141666. doi:10.1371/ journal.pone.0141666, 2015.
Written by Fiona Wong, PhD