Stethoscopes listen to your body. These acoustic devices have been around since the 19th century and are still the norm for auscultating or examining the internal sounds of your body. But a team of researchers at MIT have developed an ingestible sensor that could measure your vital signs from the inside, specifically from the gastrointestinal tract. The new sensor, packaged inside a silicone capsule that's the size of an almond, is expected to make both short and long term assessments easier on patients. Beyond hospitals, it could also help monitor soldiers and assist athletic training programs.