Key points from article :
Puffer fish like inflatable smart pill can be the next generation of ingestible monitoring devices.
Made from two layers of hydrogels, inner layer of absorbent particles and an outer protective layer.
In 15 minutes it expands to the size of a ping-pong ball in the stomach and stays there.
Can survive strong contractions and acidity inside the stomach.
Drinking a calcium solution shrinks the ball to its original pill size that can be passed out with stools.
Could monitor the progress of gastric tumours or ulcers over weeks.
Research by Massachusetts Institute of Technology published in the journal Nature Communications.
