Caltech Researchers Announce Smart Capsule to Measure GI Tract Health
Posted on June 30, 2025
Your doctor may one day ask you to follow this smart capsule. Researchers from Caltech have developed a smart capsule called PillTrek, which can measure pH, temperature, and a variety of different biomarkers. PillTrek 7 millimeters in diameter and 25 millimeters in length.
Wei Gao, professor of medical engineering at Caltech and a Heritage Medical Research Institute Investigator, says, "We designed this pill to be a very versatile platform. From an electrochemical-sensing point of view, it is very powerful. It has the ability to measure metabolites, ions, hormones such as serotonin and dopamine, possibly even proteins as well. And all within the gut, which is a complex environment."
Here is a list of what PillTrek could measure as it travels through the human GI tract:
- pH levels in different regions of the gut
- Temperature throughout the gastrointestinal tract
- Glucose concentration
- Serotonin levels
- Dopamine levels
- Other small-molecule metabolites
- Disease-related proteins or biomarkers
Gao says that he is working with co-author Azita Emami, the Andrew and Peggy Cherng Professor of Electrical Engineering and Medical Engineering at Caltech, to find ways to make the pill even smaller.
A research paper on the capsule was published in the journal, Nature.
Image: Jihong Min and Wei Gao