Proteus Biomedical has developed a system that monitors pill taking and its effects, using pills that report when they’ve been taken and sensors that monitor the body’s responses, allowing doctors to monitor compliance and side effects.

Each pill contains an “ingestible event marker” (IEM), a sand-grain-size microchip with a thin-film battery activated upon ingestion. Each IEM sends a unique high-frequency electrical current throughout the body’s tissues, logged by a receiver on a body patch or subcutaneous insert. The receiver also contains sensors that monitor physiological parameters such as heart rate, respiration, and bodily movement.