Each year more than 60 million people in the United States suffer from gastrointestinal (GI) problems, of which over a third (21.7 million) lead to hospital admissions which can put a strain on the healthcare system.1 GI disorders affect the whole digestive system, a complex network of vital organs, including the mouth, esophagus, stomach, small and large intestines, and liver.
Image Credit: MIT
Diagnosing the precise location of a particular disorder can be challenging and require expensive and uncomfortable testing procedures such as gastroscopy, endoscopy, X-Rays, and CT and MRI scans. Recently, a group of engineers at MIT and Caltech have revealed their design for a tiny ingestible biosensor that can be tracked as it moves throughout the digestive tract.
The mini-biosensor could usher in a new wave of monitoring capabilities allowing doctors to diagnose GI motility disorders such as gastroesophageal reflux disease and gastroparesis.
Many people around the world suffer from gastrointestinal dysmotility or poor motility, and having the ability to monitor gastrointestinal motility without having to go into a hospital is important to really understand what is happening to a patient.
Giovanni Traverso, Assistant professor at MIT and Gastroenterologist at Brigham and Women’s Hospital
The team’s research was recently published in the journal Nature Electronics.
In the paper, the team describes how the tiny sensors detect magnetic fields generated via an electromagnetic coil located outside the body. The biosensor’s position is calculated by determining the strength of the magnetic field, which fluctuates depending on the distance the biosensor is from the coil.
The innovative biosensor could offer a simple and straightforward alternative to more invasive procedures such as endoscopy and help diagnose GI motility disorders. Moreover, the team claims that the technology could be used off-site and in a non-clinical setting such as the patient’s home.
Of those suffering or reporting symptoms of GI disorders in the US, around 35 million are classed as GI motility conditions which can occur anywhere in the digestive system.2 The concept of the biosensor derives from the idea that a small capsule could be sent and tracked through the digestive tract.
Because the magnetic field gradient uniquely encodes the spatial positions, these small devices can be designed in a way that they can sense the magnetic field at their respective locations.
Saransh Sharma, Co-Author and Graduate Student, Caltech
“After the device measures the field, we can back-calculate what the location of the device is,” Sharma continued.
Depending on the movement of the biosensor, doctors would be able to determine exactly where and how the biosensor moves through the digestive tract and determine where any blockages may appear.
With the internal biosensor moving through the body, a second electromagnetic sensor could be affixed to the body. Furthermore, the ingestible biosensor would include a wireless transmitter that can communicate with an application on a computer or smartphone by beaming back its location at regular intervals.
Our system can support localization of multiple devices at the same time without compromising the accuracy. It also has a large field of view, which is crucial for human and large animal studies.
Azita Emami, Professor of Electrical Engineering and Medical Engineering, Caltech
Eventually, the biosensor would be excreted as it completes its journey through the digestive tract. The team was able to determine that the data and measurements they acquired demonstrated excellent accuracy; within 5 to 10 mm.2
The team is now intent on developing ways of manufacturing and scaling up the processes for the system to detect a more complete range of GI disorders. They believe that this system could break down the barriers to assessing and diagnosing GI disorders and give doctors access to a wider range of data to improve clinical conditions.
References and Further Reading
- Digestive diseases statistics for the United States (2014) National Institute of Diabetes and Digestive and Kidney Diseases. U.S. Department of Health and Human Services. Available at: https://www.niddk.nih.gov/health-information/health-statistics/digestive-diseases
- Anne Trafton | MIT News Office (no date) Ingestible sensor could help doctors pinpoint gi difficulties, MIT News | Massachusetts Institute of Technology. Available at: https://news.mit.edu/2023/ingestible-sensor-could-help-doctors-pinpoint-gi-difficulties-0213
- Sharma, S. et al. (2023) “Location-aware ingestible microdevices for wireless monitoring of gastrointestinal dynamics,” Nature Electronics [Preprint]. Available at: https://doi.org/10.1038/s41928-023-00916-0