Researchers have developed an ingestible pill that utilizes magnetic fields to precisely track its movement through the gastrointestinal tract. The findings, published February 13 in a Nature Electronics study, may facilitate the diagnosis and treatment of gastrointestinal (GI) disorders, according to the authors.
GI disorders affect more than one-third of the world’s population, including about 35 million people in the U.S. Diseases including gastroesophageal reflux disease and gastroparesis can result from abnormal gut motility where ingested food moves through the GI tract too quickly, too slowly, or fails to move through the tract.
GI disorders can occur in any part of the digestive tract. They are usually diagnosed using invasive endoscopies, nuclear imaging, or x-rays, or by inserting catheters containing pressure transducers that sense GI tract contractions. Complete diagnoses may require repeated evaluations in a hospital setting.
The researchers wanted to come up with a less-invasive alternative that could be done at home. They sought to develop a capsule that could be swallowed, then send out a signal revealing its location within the GI tract, allowing doctors to identify the problematic portion of the gut.
They developed a tiny sensor that works by detecting a magnetic field produced by an electromagnetic coil located outside the body -- for example, incorporated into a backpack or jacket. The strength of the magnetic field becomes weaker in a predictable way as the distance from the electromagnetic coil increases, so the sensor’s position as it moves through the GI tract can be calculated based on its measurement of the magnetic field.
The ingestible sensor includes a wireless transmitter that sends the magnetic field measurement to a nearby computer or smartphone. The system can be programmed to take measurements at specific intervals.
The goal is to provide a realistic assessment of GI motility -- the movement of food from the mouth through the esophagus, stomach, and small and large intestines -- as patients go about their normal activities.
The researchers used this technology experimentally to track the sensor as it moved through the digestive tract of large animals, and was eventually excreted.
The researchers contend that their smart pill offers a field-of-view several orders of magnitude higher than previous microdevices. By offering an alternative to invasive procedures, such devices may lower the barrier for people to be evaluated, potentially providing more accurate and efficient diagnosis of GI disorders, and more-precise targeting of therapeutic interventions. The researchers hope to work with collaborators to develop manufacturing processes for the system and eventually test it in human clinical trials.
“The smart pill represents a more accessible and efficient approach to assessing GI motility that can benefit both patients and medical providers,” lead author Khalil Ramadi, an assistant professor of bioengineering at New York University, said in a statement. “This is a new frontier for medical diagnosis and evidence-based treatment, and has the potential to revolutionize how we can most effectively address health challenges that impact millions of people worldwide.”